So of course, they’re going to be more likely to donate. Once you scale outside of those groups into groups of people who don’t care as much, and are less invested in the technology, you get less donations.

This is true with how things are now, but an ad free internet would look very different, and users would behave differently and have different expectations.
Note that I'm not arguing for a total non commercial Internet, things like subscriptions and Steam are fine, it's things like Google Meta Twitter and the likes, where the users are actually the product, and the customers are the advertisers.

PeerTube exists if you’re interested, by the way.

Yes I know, but youtube makes it irrelevant, because everybody post there.