My only real critique of academic books, was that the exercises varied A LOT in difficulty. Some books had exercises that seemed to assume that the reader had been a honors student, and thus able to pre-process/setting up the problem with intricate identities and what not, before coming to the part where you apply some theorem.
Now - no big problem if you worked with very keen math students, and they'd show you that, or if your TA could give some pointers. But you could easily get completely stuck, if you were using these texts for, say, self-study.
I've also found it way too easy to just convince myself I know the material and move on without actually doing any problems when I was self-studying. Thankfully I came across a Discord server that is run by a math PhD where he assigns problems and corrects proof for self-learners. Best thing that has ever happened to me in learning maths, and I have since finished several undergraduate textbooks and am working on upper undergraduate/graduate ones currently, with problems assigned from him and guidance/proof critiques.
All of this to say, is it's really necessary to have guidance with it, and to make sure you actually do problems, not just convince yourself that you know the material.
Hey, this Discord server seems to be a valuable resource. Do you mind sharing where to find it? I would love to try to get a deeper dive into some math subjects sometime in near future.
Now - no big problem if you worked with very keen math students, and they'd show you that, or if your TA could give some pointers. But you could easily get completely stuck, if you were using these texts for, say, self-study.