Why do you think there is a limit at all? What is it about higher level math that is intrinsically incomprehensible to a subset of people?
I suspect that the limit is actually in research and discovery, not comprehension. Calculus took some brilliant minds to develop but now it can be taught to most high schoolers.
As detailed in the article, my conclusion of there being a limit does not rest on the assumption that higher math is intrinsically incomprehensible to a subset of people (though, unrelatedly, I would expect that to be true in some cases).
In the article, the key underlying assumption is that the further you go in math, the more energy it requires to learn the next level up -- and everyone's "energy vs level of abstraction" curve is shifted based on their cognitive ability and degree of motivation/interest.
Here is a quote from the article that gets at the main argument:
"As Hofstadter describes, the abstraction ceiling is not a “hard” threshold, a level at which one is suddenly incapable of learning math, but rather a “soft” threshold, a level at which the amount of time and effort required to learn math begins to skyrocket until learning more advanced math is effectively no longer a productive use of one’s time. That level is different for everyone. For Hofstadter, it was graduate-level math; for another person, it might be earlier or later (but almost certainly earlier)."
I suspect that the limit is actually in research and discovery, not comprehension. Calculus took some brilliant minds to develop but now it can be taught to most high schoolers.