Yes, and you're okay with having 20 to 30 notifications at all times just to run open source apps, or would you say "this is too annoying, I'll switch back to the closed ones that spy on me".
If you want the open source products to win, they need to be able to provide the same usability as the proprietary solution. This is not possible here - you need Google's FCM or you get major disadvantages, and this is problematic.
I've filed a complaint with the EU, this seems like the only option I've got left. I can't tell everyone running a bouncer to register with Google, I can't relay all messages of all IRC users through a server of mine, and I can't bake in a Google API key into IRC bouncers (as that violates Google's ToS)