Thanks for the detailed response Alexander! This is definitely more helpful. A few follow ups to your numbered responses

1. Splitting large corporations into smaller entities doesn't seem like a bad thing to me - in the US the Antitrust Laws are specifically set up to do this.
2. Hm, yea, I see your point. In my head the shareholders were simply the financial backers of a company it was the board members who make decisions like when and were to relocate a company. But I realize now that shareholders are the ones that elect (and can remove) board members so never mind.
3. (same response as #2 above)
4. Hm, yea, but I see many of the expected difficulties as ultimately beneficial: e.g. companies may put more value in things that are long-term important to people, like the environment and well-being of future generations; rather than purely economic value
5. The international trade agreements thing is really interesting! I definitely did not know that.
6. That could be. But there are financial instruments that are pretty good at finding this type of fraud. A company may be able to fudge the numbers by a percent or two, but not in a major way.

Points #2 and #5 you bring up are definitely deal-breakers so thanks for explaining those. I do think the idea would still be much better than the capitalist "money-before-all-else" & "growth-must-never-stop" mentality we're in today though. And it seems both #2 and #5 would be a non-issue if such a system ever made its way into some sort of global economic policy, applying to all companies, and benefiting all people (regardless of country.) Obviously a dream very far fetched, but still one I see as possible and worthwhile in the long-term.

Genuinely curious - what do you think is most likely to go wrong? I imagine there would be quite a lot of corporate pushback via lobbying... is that what you mean?

Not sure I understand... Can you elaborate?

Law proposal: After a company makes over a 500 million USD in revenue 2 years in a row, the citizens of the country it operates in automatically become the company's shareholders and board members. There could be a more nuanced version of this that gives the public only some percentage - say 50% - of voting power and company's profit so that there is still strong incentive for the existing shareholders to stick around