

The project’s official repo should probably exist in a single location so that there is an authoritative version. At that point p2p is only necessary if traffic for the source code is getting too expensive for the project.
Personally I think the source hut model is closest to the ideal set up for OSS projects. Though I use Codeberg for my personal stuff because I’m cheap and lazy
If you’re able to easily migrate issues etc to a new instance, then you don’t need to worry about a particular service providers getting shitty. At which point your main concern is temporary outages.
Perhaps this is more of a concern for some projects (e.g. anything that angers Nintendo’s lawyers). But for most, I imagine that the added complexity of distributed p2p hosting would outweigh the upsides.
Not saying it’s a bad idea, in fact I like it a lot, but I can see why it’s not a high priority for most OSS devs