Exactly. If you live in a high tax / high social benefit country it isn't so bad, but if you live in a no tax (but high income, high cost) country like the UAE it would be painful. The Foreign Earned Income Exclusion is like $100k but that isn't so much in some countries. Luckily US income taxes are quite (scandalously) low.
(And if you live in the UAE that US passport will be really valuable if you need to avoid having you hand chopped off for pissing off the wrong people.)
take someone who makes a million+ dollars in california. Their marginal rate is 50% (37% federal + 13% CA, and with the note that the SALT limits due to Trump, dont really get them 37% back on the state tax anymore).
compare this to most european countries where your income tax rate at the top is 50% or less.
now, they have other taxes they pay (social and the like) outside of income taxes, but so does the US. FICA and ss fees also "taxes" in a way.
The marginal rate is really not particularly relevant unless you earn far more than that, which most people don't. What matters is the effective rate, and even California, which is one of the highest taxed states in the US, and so misleading if you want to talk about the overall US tax burden, is lower than a lot of Europe.
I agree with you they're not particularly low, though, especially when factoring in what you get or don't get. E.g. add health insurance into the picture and starts to look very different.
The US is pretty middle of the road in terms of tax.
(And if you live in the UAE that US passport will be really valuable if you need to avoid having you hand chopped off for pissing off the wrong people.)