I agree that all 'sources' of knowledge must be vetted before taking them seriously. And yes, on a forum, you can have any number of people saying any number of things, but there's much more 'fish knowledge' collectively on a forum like this, or a specialized forum like Planetcatfish.com. A member or two may be way off base, but the collective of the group will normally get to what is currently considered 'best practices'.
Choosing a Youtuber based on upvotes versus downvotes or subscribers seems like a poor basis to me. Most youtubers are about entertainment, not education. That said, there are some very good youtube videos out there that shares good information, but there's an even larger number of videos out there that are either flat wrong, or are perpetuating old husbandry techniques. In the forum, more eyes of people up on the hobby will see what's being posted and focus the discussion towards current understanding.
And the biggest problem with a new person to the hobby using youtube as a resource is that generally speaking, folks new to the hobby don't know what they don't know. And fish, unlike a dog or cat, have a very hard showing that they are being kept improperly until the damage is already done and its too late to do much about it. Further, the fish can 'look' appropriately kept in a youtube video, as I've sadly often seen... with bala sharks side by side with neon tetras and mollies. And for a short period of time, its all hunky dory. But, does someone new to the hobby know that? They look 'fine'. But, the bala shark (honestly, shouldn't be in the hobby) requires a tank that's at least 8 feet long, preferably longer... should be kept in large numbers... and without small 'bait' fish... mollies should be in hard water, neon tetras in soft water. But... for a short period of time, while the balas are young, while the mollys are fighting to adapt to the wrong water... before the 'shimmies' set in, it will look good. Its a great display to have a ton of fish in the tank, but its also not sustainable over the long haul.
Youtube is unfortunately, as bad for the hobby, as it can be good for the hobby. Which is why I suggest going to some sources that have fish profiles available to learn what each fish species requires for proper keeping, than just a Youtube video which could be a very hit or miss proposition.