Agreed - my CS degree exposed me to a bunch of low level 'algorithms & data structures' type stuff + a bit of assembly, prolog etc + some math stuff all of which I likely wouldn't have gone out of my way to learn on my own unless it came up in a very obvious way in a problem I was trying to solve. But like 95% of the actual large scale software engineering type work (read: actually building useful software) I learned on my own by building unnecessarily over engineered side projects, or by building stuff while working.

(as an aside: "don't overengineer things" is great advice when your goal is to actually finish creating something useful, but imo if you're coding to learn then horrendously overengineering everything is super valuable to the learning process - you should totally set up a full custom CI pipeline, design your own networking protocol, write a parser for a DSL etc etc in service of your dumb little tic tac toe game or whatever you're making - you will learn things)

I have a CS degree myself but most of the code I wrote/read during college wasn’t a part of any class.

I treated GLSL how others treat Civilization VI. “Just one more shader” - “Oh no it’s 4am”.

Even a degree is self taught. The assessment is typically pretty decoupled from the content. You could say "people that have taught themselves a degree course have a better understanding than those that learnt just enough to pass the assessment".