it depends. Its not like every user and question requires a new account. There was a time where these companies had a Reddit group instead Discord. Its the same effort to create an account one time, but then it can be reused. Also there is this login with existing accounts (like Google or other methods), as a secondary option.

If we are speaking about a dedicated forum, that's another thing. But since I gave up Reddit and because Fediverse is small, I started back creating accounts for forums. But only if really want to be part of it. But yes, agreed this is not convenient and Discord has a plus point here. Also Discord is integrated in other services as well (I think on game consoles, not sure).

I see its pros and cons and why its successful. Also there is no better alternative for what it does. I'm just critical about the negative impact of it. I'm so glad that StackOverflow is not close like Discord.