From what I understand (and note that this is unsubstantiated, because we just simply don't have the same size userbase/activity here), while lemmy is fairly good, piefed is supposedly even better.
The caveat here is of course that over time, software maturity and changes in prioritization of features (sacrificing efficiency for functionality or ease of use usually) results in certain decisions being made that affect the resource requirements.
It happened with lemmy (it used to be way more efficient than it is now), and it will happen to piefed too.
You don't have to, your existing account will work perfectly fine.
But on the other hand, we're not rationing them out based on how many you already have either!
Go to https://lemmy.blahaj.zone/link for a code you can use to get instant registration approval.