Honestly, I don't think preventing ad blockers is abusive. Hosting videos for free is simply not sustainable. It does not work. We aren't entitled to getting everything on the internet for free.
Google isn’t exactly struggling to make ends meet. They seem perfectly okay to be losing money on search. YouTube is no different.
I’m serious, but philosophically, the onus is clearly on us to get rid of our addiction. But Youtube is a quasi-monopoly of random micro-conferences. Nebula and Vimeo aren’t on the same market. So basically we specifically like Youtube. But I’d never pay Google after what they did to James Damore.