I don’t fully understand how lemmy works completely yet. But for example I made an account at Division by zero and subscribe here to post. Is it not just a more inconvenient version of making a reddit account and being able to post practically anywhere?
Also what’s the difference between making an account at one instant and just making one centralized account for the social media?
The practical benefit is when things go wrong.
Imagine that you’d rather not deal with the Reddit admins, for whatever reason. You have two options: either you suck it up and deal with them, or throw away all Reddit content, communities and people, because of those admins.
Now imagine that you had some issue with the administration of your Lemmy instance. You still have both options above, plus a third one: migrate to another instance. You still have access to [mostly] the same content, communities and people as you did before; but you don’t need to deal with the admins of your older instance. You can eat the cake and have it too. That’s exactly what I did rather recently by the way.
In theory, yes.
In practice, I strongly disagree with a number of decisions by the admins of my instance, but I’d rather keep ownership of the comments I have posted and would like to be notified if anyone ever replies to them in the future. Since I care more about the latter than the former, I’m not planning on moving instances at the moment. Guess I could create another account elsewhere, but I’d still have to check out the account on the old instance every once in a while. Plus I’d like to have a unified posting history. It sucks, and the technology is not quite there yet, but I hope true migrations between instances become a thing sooner than later. As far as I have been told, true migrations aren’t yet a thing even on Mastodon.
I hope that content migration (what you called “true” migration) becomes a thing in the future.
That said, the burden of checking your old account once in a blue moon is by no means that big. And if someone replied to you months after you posted something, odds are that the person can wait a bit before you reply them. You can also link your old account in your new one’s profile and vice versa, for more pressing matters.
So while I get your point (and it is a fair point - the migration isn’t completely costless), it’s still an option that you wouldn’t see in Reddit.