Those youtubers do not really know anything about the markets and most of the time they are just being paid to promote a coin or they have invested in that coin themselves, and they are promoting it in order to create a pump and dump on their own.

So with this in mind it is a bad idea to listen to them when they do not have our best interests at heart at all, also it would not surprise me if in the future the authorities begin to investigate those youtubers, as what many of them is doing can be considered illegal or at best irresponsible since the majority do not have any credentials which allows them to give such advice.