Fair question. A few thoughts:
The Polish tax system is a bit complicated. You could have four IT workers on four completely different tax setups. Some of them are in a gray area, some are completely fine.
Income tax is one thing, but there are hidden taxes elsewhere. For example, health insurance is also calculated from your income, so it works like an extra tax.
That said, it's not bad here. My effective rate is a bit over 20%, but I don't really care that much and never count it exactly.
What matters more to me is the cost of living, taxes on the stuff I buy, rent prices, and plenty of other things.
I also care about public services and how the rest of society is doing. I don't want to be rich among the poor. The contrast I saw in LA and SF was terrifying.
Call me crazy, but if my government doubled my taxes, I think I'd still stay. Just please don't tag my prime minister in this thread.