In the UK there's already a higher-than-50% marginal tax rate between £100 and £120k because you lose your personal tax allowance.
Edit to clarify: if your salary is £100K and you get a £10K raise, you see almost none of it in your payslip. But if you’re on £120K and get the same raise you get to take a good chunk of it home. That’s what seems silly to me.