To add information on that the other person didn’t, YouTube was purchased by alphabet in 2006, it was purchased in a very unstable state, it was bleeding money, but they wanted it because they saw potential in the platform for Data Tracking and video analytics along with the fact that it had a very high traffic ratio.

When they purchased it one of the first things they started working on was trying to turn it to be green instead of red, but despite this they still didn’t start seeing any real decent change until about 2009, and it wasn’t until 2015 that the platform itself started running in the green.

All this happened with YouTube being one of the most popular video platform sites out there. YouTube doesn’t have to do anything to actively block competitors from doing it, with their established market dominance, search engine self promotion tendancies(there was an ongoing lawsuit in Australia regarding this) and the amount of sheer money they have, no company is going to try to compete, the closest arguably is likely twitch but they are pushing the reverse direction with streaming instead of video hosting