The 100 - 150 ton numbers that SpaceX has offered over the years are always referring to the fully-reusable version launching to LEO. I believe even Falcon 9 (though not Falcon Heavy) has essentially stopped offering expendable flights; the vision for Starship is for them to be flying full-reusable all the time.
That said:
Agreed with you that the heat shield (and reusable upper stage in general) seems like it could easily just never work (or work but only with expensive refurbishment, or only from returning from LEO orbits not anything higher-energy, or etc), perhaps forcing them to give up and have Starship become essentially a big scaled-up Falcon 9. This would still be cheaper per-kg than Falcon 9 (economies of scale, and the Raptor engines are better than Merlin, etc), but not as transformative. I think many people are just kind of assuming "eh, SpaceX is full of geniuses, they've done so many astounding things, they'll figure out the heat shield", but this is an infamously hard problem (see Shuttle, Orion, X-33...), so possibly they'll fail!
Some other tidbits:
Personally I'm doubtful that they ever hit the crazy-ambitious $20/kg mark, which (per Thomas Kwa) would require not just a reusable upper stage (very hard!) but also hyper low-cost, airline-like turnaround on every part of the operation. But $200/kg (1 OOM cheaper from where Falcon 9 is today, using the rumored internal cost of $30m/launch and 17.5 ton capacity) seems pretty doable -- upper stage reuse (even if somewhat ardurous to refurbish) probably cuts your costs by like 4x, and the much greater physical size of Starship might give you another almost 2x. Cheap materials (steel and methane vs aluminum and RP1) + economies of scale in Raptor manufacturing might take you the rest of the way.
Ex-aerospace engineer here! (I used to work at Xona Space Systems, who are working on a satellite constellation to provide a kind of next-gen GPS positioning. I'm also a longtime follower of SpaceX, fan of Kerbal Space Program, etc) Here is a rambling bunch of increasingly off-topic thoughts:
dunno! some speculation:
presumably because to improve airplane wifi, you'd need to launch dozens of rockets to deliver a massive new constellation of orbiting satellites in order to deliver an order-of-magnitude improvement over Intelsat or whoever usually provides wifi connections to planes.
The good news is that SpaceX has done this, with their Starlink constellation! (Others like OneWeb, Baidu, and Amazon's Project Kuiper are also doing similar stuff.) But not every airline / airplane has upgraded to new Starlink recievers yet. So, most planes (and cruise ships, and etc) still have slow Intelsat/Globalstar internet, but others have indeed seen huge upgrades in internet speeds.
But this would make it sound too much like AI-related philanthropy is all they do...
"Coefficient Giving sounds bad while OpenPhil sounded cool and snappy." -- OpenPhil just sounds better because it's shorter. I imagine that instead of saying the full name, Coefficient Giving will soon acquire some similar sort of nickname -- probably people will just say "Coefficient", which sounds kinda cool IMO. I could also picture people writing "Coeff" as shorthand, although it would be weird to try and say "Coeff" out loud.
This is an inspiring post, so now I'd like to imitate some of the stuff you've done! I'd love it if you could post some pictures of what the installed RGB strips look like, in particular. I'm interested in setting up a bunch of smart-home lighting, and these light strips sound pretty cool, but it's hard for me to picture how exactly these are mounted and how they look when installed.
[insert joke about how publishing fresh JVN tokens will accelerate AGI timelines]
Another potential reason to sell sooner rather than later:
For anyone considering niplav's offer, the most obvious tax-deductible-in-Germany donation options for EAs / rationalists is probably Effektiv Spenden's "giving funds":
Lots of good options! (Personally, I won't be itemizing my US taxes this year, so I won't benefit from charitable deductions even to the US-based Manifund. So, in the name of maximum tax-efficiency, ideally somebody who does itemize their US donations should take niplav up on their offer!)