YouTube has a bunch of issues:

1/ climate change:

• A big centralised server needs lots of power, of cooling, a big pipe for upload/download,
• algorithms, metrics, content id, big size imagery (4k), all this is really needing a bunch of energy in itself to run,
• advertising in general is an ecological nightmare.

2/ monetisation:

• content id is a gamble for creators. A video can be demonetised for the dumbest reasons under the pretext of copyright infringement,
• no one knows how the algorithm works, it means one video can be suggested to a lot of people and the next one won't. So income is randomised,
• the purpose of monetisation for content creators exist to legitimate the advertising and the monetisation of user's personal data's. Not the other way around. YouTube is not a platform made to retribute creators.

Going on Peertube could mostly fix every ecological problems for the lost of the uncertainty of the monetisation system.

Plus there is a psychological weigh on creators that goes with the monetisation and algorithm of YouTube.