Actually there are guys that very good instructors, well learned in everything about Bitcoin and the blockchain technology, though there are still some guys that are also posting videos on YouTube just to get followers but they are inexperienced.
I had watched videos on market indicators for different Bitcoin trading ideas, and many of the YouTube videos on mastering the Bitcoin market trends are excellent.
In addition, is learning Bitcoin on YouTube is better than just reading books by some authors, you will acquire more exposure watching Bitcoin lessons on YouTube than reading books.