I only ever joined Discord for friends. Leaving would mean losing all friends, not even a select bunch. They're not moving and while some may care that it's upsetting, it's a collective bunch that needs convincing. Friends of friends of friends. People aren't jumping ship for one person to also not have their other friends not jump ship.
Reddit is a community but doesn't have the more casual chat that friends use (well they have it now, but it was never good).
Discord pretty much has to burn bridges like Reddit did before anyone moves.
We start by mentioning software freedom in everyday converations, in plain english, over the long term. We should not expect anything without creating its foundations.