That depends. Just how long are you on youtube for every day? I find it a little hard to believe you could exhaust everything of interest, but I don't think it's impossible. I hardly spend any time there. Maybe you should broaden your horizons. Between music, news, science, history, anime, movies, girls, nostalgia and gaming interests I have a lot of categories to pick from. And liking about 100 bands helps too. I've actually found new bands by reading through the comments under the videos of bands I like.
I see three solutions:
Search more creatively.
Like more stuff.
Spend less time on youtube.
I also have to say my experience is different than yours. I never go to YouTube just to be entertained. I usually go there to look something up for the purposes of sharing it or for refreshing my memory then I stumble onto other interesting things and spend too long there. It's like looking through an encyclopedia that way. But is being bored of youtube really a bad thing? Well I'm rambling so I'll leave you at that.