Right, like I said, you just lazily multiplied everything by inflation. But what you didn't take into account was the income growth of the 1% over the last 40 years, and that those gains -if applied to pre-1980's rates- would result in a much higher effective tax rate, not to mention a much higher revenue amount (both gross and as a % of GDP) because incomes for the 1% have grown the last 40 years at the expense of income growth for everyone else, which has remained largely flat.
So when you put the tax code back to what it was pre-1980, and apply it to 2019 incomes after 40 years of income distribution, you end up collecting far more revenue than you did before because the marginal rates are higher, and the incomes for the top 1% are higher.
So none of that was accounted for in your argument. It's pretty obvious why.