Check the percentage of total income vs. percentage of total taxes paid. The system has become more progressive even ignoring the increase in income.

How can you ignore the increase in income?

I'm not claiming I know what is actually happening in the US, it's complicated and I haven't spent enough time looking at it to be confident.

However, it's true that if there is a) an increase in total income that b) is entirely captured by a small percentage of people, then naturally their share of the total income tax paid will increase and everyone else's will decrease as a fraction unless the system is regressive in some way.

"Progressive" here doesn't mean higher earners pay more in aggregate, it means (by definition) that their marginal rates are higher that people with lower income.

What is means is if you control for income, the top 1% are paying a bigger share of total income tax.

So even if they weren’t earning more, they be paying more taxes.

Even if you taxed them to the bone it wouldn't be enough so you're going to need to tax the bulk of the commerce instead of just the residuals after it falls into their relatively idle hands.