Agreed. About 20 years ago, I used the Emacs w3m support to let me browse HTML programming language books while coding on a 48 MB RAM laptop.

https://www.neilvandyke.org/w3mnav/

https://www.neilvandyke.org/quack/

https://www.neilvandyke.org/linux-thinkpad-560e/

Getting docs into an efficient "IDE" is still nice. Just yesterday, I was using nov.el to occasionally reference Blandy et al.'s Rust book in Emacs, faster than I could the PDF or in a dedicated ebook reader program.