>>508615>And how will you measure it?
That is exactly the problem. When you study something like CS, you're measured (although with debatable quality) through tests you have to pass. When you teach it to yourself, 1. no employer can be sure of whether you employ a skill set or not, because no one will have you write all the tests for them (test code is different) and 2. you can't be sure yourself.
Of course you can learn abstract stuff like formal grammars or how to mathematically prove your code works using Wikipedia or Youtube tutorials like it's usually done in 3D, but you'll have a damn hard time without someone to answer your exact questions. Just think about how many people come here to get their questions answered and it usually takes one or two sentences. It's nothing like that in CS.
For most useful study fields, people don't go there for the lectures, they go there for the tutorials so they can ask questions.