Prefer, overall Lemmy, but probably not by as far as others here.

I like the large user base of Reddit. There’s more or less everything and anyone (fields/groups). You could search for something on the internet and limit yourself to Reddit to get higher quality results. Lots of users for lots of years.

On the other hand, Lemmy feels more or less just like one subreddit. You can come here, talk about Linux, programming and privacy even in most unrelated communities and people will just catch on no-problem. But outside that, it’s quite empty.

That’s users. Technology I have issues with on both sides.

Centralized media can get huge and stable, but also enshittify and shut down at once. However, there is no decision making in server picking, and all content is just there, immediately available in one place.

Lemmy has issues. Federation is interesting, but doesn’t work as I’d like. One instance shuts down, yes, the content remains scattered around other instances, but not all of it on each instance, it won’t federate anymore between the remaining ones, and as instances keep shutting down and popping up, it eventually dissapears.
What I’d hope for is torrent like copying. New instance joins in and begins synchronizing from all other instances to load balance between them. Once that’s done it fully comes online and synchronizes new content on the go.

But that also has issues. It doesn’t scale. Maybe the data could be split between the instances with some redundancy, but I am not sure how to do that well, and how should it be retrieved on demand quickly and efficiently.
Plus, how to make sure the data still remains the same. I don’t mean at the time of instance death, but before. Let’s say boykisser.webp is stored on ServerID69 and ServerID420. ServerID420 dies and ServerID80085 decides to keep redundancy and copy it from ServerID69, but the expected hash doesn’t match and the image is now gone. This could probably be solved in larger network by just having far more copies, and I just invalidated that like how one person doesn’t kill a torrent.

But that’s not how it works. Not even the list of instances and communities is federated like that. Best bet to find communities is going to lemmy.world and searching for it there. And with federation bots, we get back to low scalability.