> Math in its core has always been abstract. It’s the whole point.

I don't think so. E.g. there may be some abstractions in numerical linear algebra, but the subject matter has always been quite concrete.

It is not a matter of what you think it is a logical fact, part of the definition if you will.

What you call concrete - were the origins of math as we know it. Geometry, astronomy, metaphysics etc they all had in common fundamental abstract thing that we call math today.

Saying “math got abstract” is like saying “a tree got wooden”. Because when it was a seed - it wasn’t yet a tree in a full sense.