I'm on MBin. Your username is displayed as: walden. I can mouse over that to learn that your full username is @walden@sub.wetshaving.social.

This is the same thing as email domain names and display names. Yes, scammers still exploit that, too, but for the most part, people have gotten used to also looking at the actual full email address, and not just the display name or mailbox name. The same can happen here.

Still, I would much prefer if the default view here showed the full username and not just the display name.