Now, we are social animals, and we grew to value these thing for their own right. Societies valued strength and bravery, as virtues, but I guess ultimately because having brave strong soldiers made for more food and babies.
So over time, we tamed beasts and built tools, and most of these virtues kind of faded away. In our world of prosperity and machine power on tap, strength and bravery are not really extolled so much anymore. We work out because it makes us healthy and attractive, not because our societies demand this. We're happy to replace the hard work with a prosthetic.
Intelligence all these millenia was the outlier. The thing separating us from the animals. It was so inconceivable that it might be replaced that it is very deeply ingrained in us.
But if suddenly we don't need it? Or at least 95% of the population doesn't? Is it "ok" to lose it, like engineers of today don't rely on strength like blacksmiths used to? Maybe. Maybe it's ok that in 100 years we will all let our brains rot, occasionally doing a crossword as a work out. It feels sad, but maybe only in the way decline of swordsmanship felt to a Napoleonic veteran. The world moved on and we don't care anymore.
We lost so many skills that were once so key: the average person can't farm, can't forage, can't start a fire or ride a horse. And maybe it's ok. Or, who knows, maybe not.
"Problem-solving" might be dead, but people today seem more skilled in categorizing and comparing things than those in the past (even if they are not particularly good at it yet). Given the quantity and diversity of information and culture that exists, it's necessary. New developments in AI reinforce this with expert-curated data sets.
It’s not.
Mathematics is fundamentally about relations. Even numbers are just a type of relation (see Peano numbers).
It gives us a formal and well-studied way to find, describe, and reason about relation.
In that case, mathematics is a demonstration of what is apparent, up to but not including what is directly observable.
This separates it from historical record, which concerns itself with what apparently must have been observed. And it from literal record, since an image of a bird is a direct reproduction of its colors and form.
This separates it from art, which (over-generalizing here) demonstrates what is not apparent. Mathematics is direct; art is indirect.
While science is direct, it operates by a different method. In science, one proposes a hypothesis, compares against observation, and only then determines its worth. Mathematics, on the contrary, is self-contained. The demonstration is the entire point.
3 + 3 = 6 is nothing more than a symbolic demonstration of an apparent principle. And so is the fundamental theorem of calculus, when taken in its relevant context.