Not that surprising. 13 billion videos is a lot cheaper to host when everyone is only looking at 10 in a loop.

There's indeed a big difference of objective between YouTube and their users because of that.

However, that's also an opportunity that YouTube hasn't realized yet, they could become a primary platform for content if they had a better algorithm and a better search, it would help them to monetize better those subscriptions.

Youtube has one of the lowest per viewer revenue and the poor discovery isn't an accident in that.

Imagine a world where there are 13 billion videos and truly only 10 worth you watching.

Are you sure you live so far from that world?

My experience of YT is totally different, FWIW.

I'm sure there's great content out there, it doesn't matter if I can't find it though.

It's YouTube which thinks there's only 10 videos worth watching, not me.

YouTube also seems to forget what videos I've watched, so I end up having videos recommended to me that I've already seen.

People rewatch a lot, so YouTube is suggesting what it thinks you might likely be inclined to rewatch, based on what other people rewatch.