I echo this request. It was my expectation actually!
I searched for my username and was shocked it was used on literally every website you checked. Then I tried a less common variant and was similarly shocked, until I realized that you were showing me fewer websites the second time around. Only then did I realize you only showed me sites where it was already claimed…
what I find annoying is that (other than HN) most places won't let you claim your username if the person has signed up, yet never posted over years (or even logged in) and places where an account was deleted.
when I signed up to HN, I had a different username. I reached out to admins and they looked at the other account that had been created but they let me have it because the person hadn't logged in since. Oh! I think GitHub did as well. (shit, I wonder if I have mixed up GitHub and HN... I'm pretty sure they're the two that did actually let me have my handle... :x)
Because some people sign up for a site early and then never use it. I can't get my desired handle on a particular social network because some dude registered 15 years ago, posted one item, and then never used it again.
I mean, obviously I'll live but it's a silly situation.
I really like how Discord handles it.
Username + 4 digit number = unique handle, but if nobody else has the same username in a server then you can just use the username to refer to them