4 pane comic of dolan on the left and spooderman on the right
pane 1 (dolan): cum join opensurce cummunity!
pane 2 (spooderman): shure! how joyn?
pane 3 (dolan): Here discord! (with discord logo)
pane 4 (spooderman with tears in eyes): y u do dis?
90% of the projects that i use and other people care about are developed by people that have the technical ability to set up and host a web server. They likely have the cash. It's not exactly outrageously expensive. If it's small enough they dont have the cash for it, they don't need it.
Im guessing the discord was more of a legacy thing, someone was like "hey im having a problem, can you contact me on discord?" and then suddenly we have the rust discord server.