You have a point but ...
Take a look at any old 50's and earlier math book. Algebra, for example. I have a couple from the 40's. They are relatively short books but you could easily master algebra by following the course outline.
The format: Description of the basic principles, example problems worked out and then problems for the student.
Now take a look at the 5 lb monsters that the kids need a backpack to carry that are now used to teach ecology/algebra. Lots of hand-holding. Political Correctness brought to a fine art but just total overkill when it come to the math. Confusing and, in the end, inadequate.
The 50's were better.
That is partly the fault of the textbook companies. The PC cops get their say naturly, since all “educationists” are lefties. Because, come on, who what kind of person wants to be an “educationist”? The same who’d be a “community organizer.” That is, someone paid not in money but ideological self-satisfaction and delusion of grandeur.
But I digress. The textbook companies have a near monopoly, and they milk that advantage to the point of absurdity. New editions every year, natch. Ridiculously overpaid authors who might not actually write a word. Glossy pictures that make sense in a coffee table book but serve in a classroom to give something for kids to instead of paying attention. Covers hard enough to side your house, accompanying CD-ROMs that no one will ever, ever use, etc.