From what little I scrolled, I didn't see any category theory. Just some elementary group theory, point-set topology, real analysis, linear algebra etc Most of it standard material for undergrad math majors.

> And stuff that used to be simple algebra is now explained as something like 'Abelian group linear transformations'.

"Simple algebra" means different things in different professions? For example, Dummit&Foote's Abstract Algebra[0] would be considered "elementary algebra" by most mathematicians. For another example, Principles of Mathematical Analysis by Walter Rudin[1] is "elementary analysis".

[0] https://www.amazon.com/Abstract-Algebra-3rd-David-Dummit/dp/...

[1] https://www.amazon.com/Principles-Mathematical-Analysis-Inte...

Yup. You can get the international version for cheap: https://www.amazon.com/Principles-Mathematical-Analysis-Rudi...