You’ve come full circle. Of course there are hosting providers everywhere, but there are no guarentees that they will still exist in the future. And if your not selfhosting, then you have to pay someone to host it for you, whereas Discord and Github are free.

And a small subsection of the “dont use discord” crowd are equally against using Github for many of the same reasons.

To be clear, I am completely okay with Discord, Github etc for foss projects.