Why doesn't engineering have good publisher

All the books lack so much the tech max was good until it shut down( I am in college from Mumbai University which is largest yet it lacks good books)

I recently purchased a tech knowledge book of computer organisation and architecture and the book is trash, it lacks contents and basic definition

For example in semiconductor physics the book didn't have numericals based on many topics in the syllabus, i got to know because of the last year paper

The main problem is the material other than the first year and some maths related, there is no good material for engineering i find. The books which are made for this lack many contents and the reference book have extra content so you have to filter out everything, i already have trouble with the subject and not having the right material makes it worse

https://redd.it/1x7fyz1
@BTechtardsReddit