Which is why the economy collapsed in the 1950s when the top marginal tax rate was 91%, and we’ve been living in a Mad Max wasteland ever since.

Very few people ever paid 91%. The reason was there were all sorts of tax shelters available at the time. This resulted in a lot of misallocation of resources. A lot of personal expenses could also be written off as a business expense, the most infamous of those was the "three martini lunch".

Reagan, in his deal to reduce the top marginal tax rates, also eliminated a vast swath of tax shelters and tax deductions.

More generally, the government consumed much less of the GDP in the 50s than it does today.