I had basically the same thought: as a user, flatpak means I'll need to install an extra daemon for something that doesn't need to run all the time, and therefo

I had basically the same thought: as a user, flatpak means I'll need to install an extra daemon for something that doesn't need to run all the time, and therefore it's right out. AppImage is better in that it doesn't need that, but it has other limitations for the packaged software. I've also used software that just plopped files into /opt/… not great, but at least it's mostly contained. If you're not going to support some users, don't be surprised that somebody else ends up doing it I guess?