"Imo text should be the main source, then use YT videos as supplemental material "

Text has its own corresponding set of unique "platform" problems.

But really, the thing spanning both is the concept of "spam". Quantity over quality seems to be winning out, and the algorithms are not doing their job of sorting the best content to the top. They do to an extent, but then they "spread" out the rest over the entire stack of quality so that it's not a winner takes it all kind of sorting.