Math is pardon the pun, fractal in nature. Geometry skills may be reasonably common, but topology and group theory for example are rarely taught in high school or their not even part of most collages general education requirements.
Go back 50 years and people may have been studying geometry but they covered significantly different areas.
Is it more or less complex than 20, 50, and 100 years ago?
How many subspecialisations have groups 9f 50, or 10, or5, or 1, who actually understand them?
At what scale of living practice does knowledge fail to be cultural and become merely transient, lodged for a few years in a few minds, perhaps mouldering for a few decades in a fiche copy of a once-read dissertation?
In terms of actually useful mathematics, not much. But, that’s missing the point. 100 years ago people studied chess as hard as they could, without machine assistance they didn’t become as skilled but that doesn’t mean chess somehow became more or less complex. Lawyers are dealing with roughly equivalent legal systems, and so it goes.
Mathematicians may have discovered say more digits of pi through useful tools, but at the core mathematicians are about as intelligent and still working just as hard. We have more mathematicians today in large part because global population has increased 4x in the last hundred years. However, go back 100 years and most people didn’t understand what hyper specialized work was being done.
