Youtube has been unprofitable since its inception and only recently it started to break even, so the Youtube that we know was indeed only possible due to centralization and Google being a giant corporation. A decentralized tube would most likely be in some ways worse than Youtube, but it would also be more free.
It is true Youtube did not have an advertisement model in the beginning and they needed a big firm like google to make things different and make it a profitable company and even then it took years to make good profit, they were getting visitors but to turn that into money it took a while and if it was a decentralized platform i doubt it will continue for a long time without a strong business model.
there is a crypto project that has a concept like youtube, but we are paid with tokens when making videos, upvotes, and shares,
the project is Tokentuber, if youtube does the same, i am sure it will be better than them following Google's footsteps