It's early days. Who knows? Maybe in a year or two, when the Federation aspect is a bit more developed, we'll have a seamless, less fragmented experience.
In my case, whenever I tell one of my friends about Lemmy, they feel like they're going to be isolated on their own little island (instance), and that they'll probably be missing out on a livelier community somewhere else. This misconception is probably the result of relying on centralized platforms for decades. Nothing inherently wrong with that, but Reddit is the perfect example of what can go wrong when you put all your eggs in one basket.
I had better luck showing them the Memmy app in action. Hope they join the community soon.
I used to use Calckey but it soon morphed into Firefish, which also didn't last long. So, as far as stability goes: Misskey may be stable, its forks not so much. I'm currently using Catodon (catodon.social) and the only functionality missing is the antennas.
On the other hand, most of the firefish crowd migrated to Iceshrimp. You can check out the Fediverse Observer to find some english-speaking instances.