I interviewed a Nintendo insider!

[VAMatt]

numberwang said:

I am surprised your channel hasn't taken off more.

There are (literally) millions of channels.  There are (literally) thousands with good production quality like this dude's.  The vast majority (nearly all) aren't profitable.  There's a lot of luck that separates the successful good ones from the unsuccessful good ones.  It isn't just luck, but that's a big part of it.