The only competitor I could see YouTube getting is if Twitch decided to chase that route. The only companies with the global infrastructure required for a service as fast as YouTube's are Amazon, Microsoft (and Google).

Microsoft gave up on Mixer, so I don't see them ever trying to take on YouTube. Amazon have Twitch, which as mentioned, could try to take on YouTube. But even with owning their own servers and just running them at cost, it would be a massive undertaking and investment.

There's a tremendous amount of work to do, that these companies are not going to throw money at for decades just to compete for YouTube's profit margins, which apparently aren't that big (if they even exist).

Sites can exist alongside YouTube, We see a lot of smaller video hosting sites, like Dailymotion, but something would have to go seriously wrong at YouTube for any of them to grow meaningfully and become actual competitors.

I'd like a competitor as much as anybody, but I'm just being realistic here. Don't underestimate the size of YouTube.