Well France is the master of all countries at taxation (they invented VAT, amongst many other kinds of taxes...). In particular when employing people, the employer has to pay employment taxes on top of the employee income (same as in the US, but at a much higher rate), and that is not subject to income tax, yet represents "cotisation sociales" (social contributions, i.e. retirement, unemployment, health taxes) that came on top of that.

Use this simulator : https://entreprise.pole-emploi.fr/cout-salarie/ and you'll see that for a 100 kEuro/year employee, what the employee sees is 55 kEuro/year (and that's before income tax). My point is that most taxation in France is not income tax, so even if a marginal rate of 45% exists, that's not where the French are most taxed (although the French would argue that "cotisation sociales" are not taxes, IMHO they very much are). Income tax is not even the number 1 tax for the French state (that would be VAT, see https://www.performance-publique.budget.gouv.fr/budget-compt...).

Not saying this is a bad thing (I wouldn't mind a top marginal rate of 90 % as has existed in the US for most of the 20th century... most people aren't subject to it), and in fact I think the French get a lot (although not enough, the state budget could be better managed) for all their taxes.