The "flexible" approach does work, but tends to be quite a drain on workers lives. Theres always someone somewhere who has to wake up at 2am for the weekly 'sync' meeting, or who doesn't see their children after school because their calendar is clogged with 1:1 meetings with all their USA reports most evenings.

I think it's getting better - a number of countries worldwide (such as Portugal or UAE) are making it easier and easier for people to work remotely as "contractors". While not perfect, it's definitely a good solution for highly skilled workers who have a strong negotiating position and can ask for all the benefits their country's labour law would otherwise assure.

There are startups aiming at solving this problem, like https://en.wikipedia.org/wiki/Deel_(company)

I’m struggling with American “superiors” who won’t have a meeting in any time that isn’t perfect for them.

If it’s not between 9:00-17:00, sorry, bad luck for everyone else.