In my experience, these YouTube channels buy that simplicity in exchange for leaving out many (important) details. Sure, college professors aren't all didactic geniuses, but making things accurate usually requires to also make it more complicated.
Sometimes you need the simplified building blocks before you can grasp the full scope, though, and sometimes the professors don’t provide the building blocks but the YouTuber does. So the “core concept” videos end up helping you understand the professor’s details.
The issue with subtitles on YouTube is that if the creator doesn't upload the transcript, the captions are auto generated and they're often wildly, laughably incorrect. Also if the speaker goes quickly it's prone to even more errors as it tries to display it quickly. Sometimes that captions are the beginning half of one sentence and then the second half of an unrelated sentence.
It's fine if you're just screwing around watching funny videos but I wouldn't want to base my understanding of a subject on them.
