Discovery and search are a clusterfuck mess on peertube.

Try Grayjay, it allows you to add many streaming platforms in one, and for PeerTube it has the option to turn on Sepia search - meaning all instances are searched and indexed together like you get for Lemmy.

I follow some channels from lemmy and you see the videos as of they were posts.

Peertube instances can be, like lemmy, federated with other instances. Meaning looking at one instance should show both its local content and the content of federated instances.

The official Peertube android app (no login required but needed for subscriptions afaik) shows you one instance at a time. You can change the selected instance, but im not sure how the app handles your logged in account instance and selected instance not being federate with eachother.

Peertubes official global search called sepiasearch will always link all results of your query to the original instance either way. There might be some nifty api thing that makes this play nice with peertube clients but im not sure.

There are unnoficial peertube apps with different approaches but the ones i tried (newpipe and thorium (reccomendations welcome!)) follow a similar pinciple to the offical android app but without account capability.

I hope that helps you with how peertube is 'intended' to be used. The way peertube gets the actual video file from federated instances is a bit beyond me but as far as i understand it its very close to torrenting.

It works exactly like Lemmy, yeah!

If your experience with PeerTube comes from their official app, the UI is kind of unintuitive to anyone familiar with the fediverse. I think they tried really hard to prioritize users not having to be signed in at all, if that makes sense?

It's supposed to, but your experience has also been mine for some reason.

The only instance I know of that is best suited for that use is peertube.wtf, who the operator of also happens to be semi active here on lemmy too.

You can add channels from other instances on any peertube instance as long as they are federating with them but the issue is that there are not many peertube instances that aren't just super focused on a certain thing and so this tends to kill the interoperability more than help it, which is why I think peertube.wtf is good for casual youtube-like use because it is federating with all of them, its difficult to do because videos are expensive to store and share so it will be slow to improve but steady to grow just like the rest of the fediverse.