Takes time and resources to setup a web page. Takes 5 seconds to spin up a discord server or a telegram group and they handle all access control. Not my preference, but for ease of deployment a lot of people prefer to launch there.
If you won't even take the effort to setup a proper homepage for your software (could literally be done in minutes these days), it probably sucks anyway.
I somewhat share this sentiment but I was also just answering the question. There are actual reasons one would want to host documentation/etc on a already realized provider vs infrastructure they'd have to configure and potentially pay for themselves.
Well then, it can't be trusted at all.
Who's to say they haven't loaded it with spyware.
Only OS's worth any privacy conscious persons time are FOSS ones.