I must have been way out of it late last night. I totally missed that you were asking why people do it and not looking for recommendations. Sorry for the spammy nonsense response to your OP.
To the latter question, I’ve seen devices that do OTP and FIDO in addition to basically storing arbitrary strings (e.g. your cc number).
I get harassment scolding me for using Lemmy to advertise when I mention any of the products by name, despite having no affiliation with any of them outside of being a user, but they’re not hard to find if you look.
I’m not even interested in the username of the person I’m responding to. I tend to ignore it completely unless there’s a comment like “lol, username checks out”.
There are very few times I will bother to check someones profile. They have to either say something so awesome that I want to see more, or have given a take so hot I want to see if they’re trolling or if this is standard behaviour for them.
While it looks like the whole Jerboa/“miscommunication” thing has been sorted out here I want to chime in to say that no, I don’t think that checking profiles for anything is a reasonable expectation.