Why Discord took off as a medium to replace forums is beyond me

My theory is that it was used as the primary form of informal communication by groups doing something, then it felt like a community.
And since everyone was there...Why not put the documentation there? Sure, it's not indexable, but the group is open-sign-up, right? Right?

Then a few years down the line, someone suggests switching to another primary storage location...Then faces huge amounts of push-back from people comfy sitting on discord.