zlacker

That is only true of income tax. Not all taxes are marginal, and several have thresholds that behave exactly as the OP described.

>>jen20+(OP)
The people arguing only seem to care about income tax and NI, ignoring that other taxes exist at almost every level on your money.

>>alias_+k8
Moreover they generally make the argument, have marginal tax rates explained and then rapidly go off looking for some specific welfare policy where this is sort of true.

Because if they knew about the welfare policy before they started typing, they would've actually mentioned it then - it's a specific problem, with several obvious solutions (i.e. don't means test at all or taper off more gently) unrelated to the concept of tax brackets (and potentially not related to the actual bracket index values themselves.