AFAIK, U.S. imposes income tax on all of its citizens, even those who reside in other countries. IIRC it applies to all earnings above $110k(?). There's also the notoriously difficult hassle of complying with FATCA's [0] reporting requirements. I would imagine that sours the value proposition quite a bit, at least for U.S. citizens. [0] https://www.irs.gov/businesses/corporations/foreign-account-...
That depends on the country. Some (I imagine most?) countries have deals with each other when it comes to taxation, to avoid double taxation.
So if you're earning a salary in, say, Israel, then you only have to pay US taxes on money that hasn't already been income-taxed in Israel. Therefore, whether you're paying more taxes than locals depends on whether the tax rate in the country is higher or lower than in the US. If it's higher, then you end up not having to pay anything extra.
That said, these things get tricky and there are lots of individual wrinkles. E.g. freelancers typically have to pay taxes either way here, afaik. Then again, those taxes aren't doing nothing - they're paying for you to have a US social safety net of some sort.