Nothing's stopping you from making ChanTube, GabTube, or whatever you find "acceptable". But, if it gets popular, be prepared to take down illegal content, filter spam, get sued by copyright holders, etc. until it looks a lot more like youtube than you intended. Or, y'know, break under the weight of the consequences of harmful speech without substantial ad income since most advertisers won't want to associate with your toxic platform.
You're right: this is a great example of the free market not solving a problem. Which is only a relevant point if you think the free market is the only way to solve problems.
A decentralized video platform not under the control of a centralized company would bypass all the issues you mention. There are technological challenges, but we've made slow progress toward solutions over the past few decades.