Each channel has a option to put your support information so people can pay you through patreon, etc. Peertube instances are offering their video hosting for free. You can put in video ads or patreon like services to enable payments. Peertube instances can ask for money as well to help with hosting costs. It’s the same business model as all other federated software. The cost of video hosting is distributed by instances and also uses bittorrent to help with sharing the load.
I meant in video ads as in “this video is sponsored by…”. At least i think that’s the case. There is no built in way to have ads in peertube. Everything would have to be supported by links to services like patreon. anyone doing what you said could be defederated.