Who wants to join?
This whole post comes from my experience joining and trying to use Peertube. The immediately obvious problem is getting creators to post on Peertube which is an entirely separate issue. Even once I did decide I wanted to join Peertube and try to find all the content I could, I still ran into issues and it just wasn't a smooth experience at all. I'm fine with that as I understand the fediverse works differently and Peertube is a relatively small project (especially compared to YouTube) and I can accept that because I support what Peertube is doing as an open source federated platform. However, most people don't care about all that and even if they hear about Peertube and creators start moving there, regular people will still struggle to use it in its current state.
"Default" instance
Creating an account is confusing and the whole "choose your instance" is extremely unintuitive for new fediverse users. Obviously this isn't unique to Peertube, but other fediverse platforms like Lemmy and mastodon have solved this by having a "default" general instance to direct people to (e.g. lemmy.world & mastodon.social).
Search/Discovery
This somewhat goes hand-in-hand with the previous point, but it's really hard to search and find new creators/videos. Part of the reason is searching in most instances will on search that instance and maybe a few other instances that are specifically federated with yours. The closest to a "universal" instance I've found is peertube.wtf, but it is extremely slow for me and sometimes just doesn't load at all. Maybe this has to do with the fact that it is also searching so many federated instances, or maybe it's because it's based in Denmark and I'm in the US. Either way, I created an account but it was basically unusable so I switched to TILvids which seems to have a decent amount of creators but isn't federated with many other instances. There's also Sepia Search but it honestly doesn't seem to perform great and it's very unintuitive to have to go to a different website to search, then the finding a creator/video but it goes to that instance, so to subscribe, comment, like, etc. you need to find a way to open that video within your instance.
Well, the problem that I see is that we do have a platform but don't have an easy way to use it. If Mastodon allows to browse the PeerTube with all other fediverse platforms together, that we just need an app that will copy Mastodon but with limitations and optimizations for only video content. I do not say that this will solve all the problems, but this can improve the experience.
Content quantity and discovery are definitely issues with peer tube but I think you hit the main issue here... Using it is a horrible broken experience right now. The few available apps are a bad experience and the websites feel cluttered and confusing. One of the core features of PeerTube is P2P sharing (give back what you take) but whether I'm using an app or browser I can never tell if that feature is actually available and working. I just want a user friendly app that plays videos and allows me to passively contribute bandwidth to channels/videos I like. I really want to like PeerTube but it's not a fun experience at the moment.
I still think it would be best to just have a "centralised" Peertube instance that can list videos from many other instances that users can sign up to and easily discover a large catalogue of content. The issue with a Mastodon style app is it could also show other random videos from Mastodon and short form videos from platforms like Loops, and those are two different media categories from Peertube/YouTube content in my mind.
Centralization kills the whole idea of Fediverse. But, what can be done is creating a special instance, that will aggregate the links to posts that contain videos in them into itself from whole fediverse. Then, store and update them in a local DB providing the API end point. And because of it will be containing only Metadata of videos, not only the database will be very small(only like a dozen GB for millions of videos), but it will also allow to search info very quickly and provide it to the users. The whole idea is that it will provide centralized ability to browse content while remaining federated, since it will not store any videos in its DB acting more like some sort of external indexation archive.
Then, I also think that it is possible to make options to not only listen to content but also to publish it through this middle point onto desired real instances. Must say that I do not sure about this second part, but first part is totally achievable. In fact, I'd be happy to try to create a system like this myself, if only my internet provider wasn't using NAT system and, at least, had lover pricing for a dedicated IPv6 address. Since using some cloud services for development and hosting of such thing doesn't provide enough control.
Right that's what I meant about a "centralized" instance. I just think it would make things a lot easier if there was one "main" server that new users could easily be directed to, create and account, and view and discover content from lots of other instances.
The existence of instances like MakerTube I think provides a good platform for dedicated creators to go to at the moment, but it would be cool if again, there was a main instance that somehow allowed uploading to other instances.