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?
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.