How exactly does Lemmy remain in compliance with laws regarding, for example, a user’s right to have all data associated with their account deleted (right to erasure, etc), or ensure that it is only kept for a time period reasonable while the user is actively using your services (data protection retention periods, etc)?

It’s not a big deal for me, just strange to think Lemmy of all places would be built to be so anti user’s data rights. The user is ultimately the one that decides what is done with their information/property, after all.