One of the many things I learned during my wife’s cancer treatment is that healthcare is designed with the cost development systems insulated to resist external influence. There is little accountability for the base cost architecture, often to the point where no one can identify the architect. 
This makes addressing inefficiencies, exploitations, and shortcomings almost impossible. 

From a regulatory standpoint, legislative action has little to target. The doctor, the technicians, the hospital, the supply vendor, the pharmacist, and even the insurers rarely set their own prices. Between every transaction there is at least one middleman who manages the cost and often their pricing guidelines are set by yet another middleman. The structure eliminates the cash flow variable from the parties in direct patient contact and leaves only the profit component as a variable. This undermines free market cost controls and performance incentives.

For hypothetical example, a hospital billing for a $10000 procedure does not receive that $10000. Third, fourth, or fifth parties receive the money and redistribute it back to everyone in the chain. That means the hospital is left with a negotiable amount of just $600 (above the line, $200 below). This phenomenally granular disintermediation of the cost structure means no party has a vested interest in individual transactions. There’s simply not enough money at that level to invest in higher stakes negotiations one might expect in a $10000 transaction. This makes volume the success defining metric. 

As I was spending countless days in hospital over the course of a year, I started counting keystrokes and mouse clicks performed by various hospital staff. Roughly 60% of all computer interaction was performed solely for billing purposes, not patient care. Billing purposes are also the primary driver in wait times. The doctors review patient records before each visit and spend much of that time reviewing what treatments they are allowed to use based on the patient’s financial means and their insurer. The highest performing doctors (a volume metric) are the ones who memorize the treatment approval criteria and don’t have to refer to the computer as often. 

The scope of the disintermediation is vast, so more examples are not useful. At the end of the day, what it boils down to is that the individual parties involved in the minutiae of patient care are insulated from each other. This makes YIMBY activism ineffective because enacting change that way only affects one tiny group within the chain and everyone else adjusts to compensate. It’s like trying to eat Jello with a cooked noodle. Huge effort with little to no reward. 

I do not have any reasonable solution. Americans have proven time and time again that adopting healthcare like developed countries have is unacceptable. The focus has to change to actual healthcare where patient outcomes are important (as opposed to focusing on billing outcomes for  providers). Increased frequency of Luigi Lobbying is unreasonable, but I think more people are beginning to see it as justified. 
 

At least on the breakthroughs what you are looking for is the "Right to Try" movement, as well as various state healthcare regenerative medicine initiatives. You need to understand that we make discoveries of treatments all the time, but the reason you hear about incredible breakthroughs and then see nothing on the market for decades is that it takes enormous investments of time and money to get them to the point where they are approved to go to market.

Right to Try laws are either Federal or more often state level laws which allow patients to access treatments which have gone through some level of FDA approved clinical trials, but have not yet gone all the way to passing all required phases for market approval. One very broad Right to Try law can be found in Montana, which allows any patient with approval from their doctor to give informed consent and access any treatment which has passed phase I clinical trials.

One unfortunate flaw of Right to Try laws is that despite it being technically legal to access these treatments, it still requires manufacturer consent (you cant just rip of companies' patents or anything), and most of these companies are pretty worried about the FDA retaliating against them if they were to make their drugs available under these state laws. There's also various commercialization bans and other regulations limiting manufacturer activity. All of that comes together to make it hard if not impossible for manufacturers to actually provide access, so they don't, so very little is available under these Right to Try laws. I'm personally looking at starting a fund to try to provide a sort of middleman for the process so companies can do this in a regulatorily compliant fashion, but it's an uphill battle even when you can provide them technical guarantees, because there's a real worry about retaliation down the line.

Another angle of "Healthcare YIMBYism" can be found in various state stem cell medicine laws, which often explicitly allow local physicians to perform treatments not approved by the FDA. Utah and Florida have both recently passed these (Florida's is passed the house & senate but yet to be signed by governor). I actually just finished writing an article on these two laws and their differences which sadly got rejected by the publisher, but can send it to you if you want more information.

Lastly, there has been a lot of pushing by the Goldwater Institute recently for Right to Try for Individualized Treatments which allows patients to access treatments based on their personal genetic code (which by default are practically impossible to get through FDA clearance processes) which has been quite successful.

This doesn't address all of your expense concerns of course, but at least on the breakthrough and getting technologies to market side of the equation, the movements you're looking for do exist. Feel free to DM me if you'd like more information.

Anybody interested in this topic should absolutely read the Niskanen report on healthcare abundance, which goes into excruciating detail on how over-regulation and entrenched interests have kneecapped the supply of healthcare (doctors, hospitals, clinics, hospital beds, etc) to the detriment of society overall.

A core aspect about the YIMBY is that housing isn't that complex. Building more housing is straightforwardly good. Nearly everyone who would benefit from having more housing. Those people who would not benefit from having more housing have an easy way to choose to rent smaller spaces.

Healthcare is not like that. Getting more healthcare services doesn't always help people. When buying a used car most people understand that they can't just trust the car salesman with the assessment of the value of the car. While the relationship between car buyer and car salesman is economically similar to that between patient and surgery salesman surgeon, people do want to have relationships of trust with their doctors.

The doctor-patient relationship has been disintermediated by not one but two parties: insurers and employers.

That seems naive. There are a lot more parties than those two that disintermediate that relationship in the US healthcare system.

Between insurers and the employers there are insurance salesman that take their cut. In addition to the official fee that the insurance salesman get paid insurance companies find additional ways to financially reward them as well. Martin A. Makary (the new head of the FDA) book The Price We Pay: What Broke American Health Care--and How to Fix is good at explaining the insurance salesman issue and a few other issues as well. 

Hospital used to get reimbursed more for an individual procedure than an independent practice (the Trump administration wants to change that). As a result, there pressure for doctors to be formally employed by hospitals. Those doctors often don't know what's actually chraged.

Insurance companies often pay a multiple of medicare reinbursement rates. Those are not set by the government but by the American Medical Association which is essentially a lobby organizations for doctors. If lobbyists for a given procedure win their fights within the American Medical Association, the reinbursement for that procedure becomes higher. 

(there are probably other parties that disintermediate  the relationship as well that don't come to my mind right now)