I have been using Lemmy for 20 days, at first I opened an account at Lemmy.world because you can join without writing a text and waiting approval. I have been enjoying the experience overall but despite the admin teans best efforts Lemmy.world has been experiencing some serious performance issues. If you want to avoid that join a smaller instance, preferably hosted in your country. I joined discuss.tchncs.de today and everything is so much faster it has added benefit of being able to see beehaw.org posts too. It will improve not only your but all other Lemmy.world users experience too.
But you can still view and interact with all content on any federated instance so why would you need another account?
If you want to switch instances.
There’s no guarantee your instance will be around forever, they are all created by random people across the world running their own servers at their own cost. People may get bored/too busy and move on, can’t afford it anymore, etc.
Also no guarantee the same people will run the instance forever, could get sold/given to new admins who ruin it somehow.
Server could get overloaded with too many people/content and not maintained properly resulting in poor quality/speeds.
Lots of reasons you may need to switch instances, would be nice if you didn’t lose 5 years worth of account history and be forced to make a new one.
That makes sense. Hopefully they’ll add migration soon.