Peertube in it's current form is not a replacement for anyone other than tech nerds and it's not gonna change unless some real changes are made to how the platform fundamentally operates.

1. The federation is currently opt in so the videos you see are largely dependant on which instance you choose. They made this choice because of the obvious problem – storage cost.
2. You're stuck hopping between instances because the content is really fragmented.
3. I don't think that there are currently ways to stream other instances' content if the content is not mirrored onto the instance that you're on.
4. No way to search through the whole fediverse for content on many instances, but it is available on some, like fair.tube.

This is just my opinion so correct me if you think I'm wrong. Many of these problems have plagued the site for a while.