I think a lot of this will come down to which specific issues someone would want to address. Even if we take away the for-profit / power hungry aspects of old social media platforms, sometimes there are legitimate use cases for having some permeance.
On Lemmy, and the few other interconnected platforms that follow this format, usernames are unique and are the core "identity" of the account. This is important to how the system works, since the content needs to be tied to something. User's can easily change their email address and display name, but the main username is the core "identity" that stays constant.
Meanwhile, users are also free to make multiple accounts, across multiple instances, if they prefer. Generally, admins (our team included) only care if someone is abusing the multiple accounts to evade bans/blocks, manipulate votes, or harass people, etc.
I personally find that this is a nice balance between user choice and chaos 😄
As for federated platforms:
Better:
- There are very few malicious trackers / algorithms (if any) that use dark patterns to dictate who can / can't make an account
- Many platforms are implementing ways to move most of the contents from an account to a new account when people want to
- With smaller independent teams, you can get personal attention from a human if you need help with recovering something. This may change over time as platforms grow/scale
Same/Worse:
- Most things on the internet can't be 'deleted' once shared. The federated internet can make this even more obvious because the content is actively shared around to multiple servers. It's like trying to hide the contents of an email. However, private content CAN be deleted. If an admin or user purges something from an account on Lemmy, that content is pretty much gone for good.
If you want to see what info is visible to whom on Lemmy: https://fedecan.ca/en/guide/lemmy/for-users/privacy-security
If you want to see the Lemmy code: https://github.com/LemmyNet/lemmy