Wait, why is Fedora making their own flatpaks? I thought the entire point is that they work on any distro and everybody gets the original source from flathub.

Just to add to the other replies you've got, as far as I'm aware there's no reason why you can't add Fedora's flatpak repo on another distro. Why you would want to is another matter, but I think the fact that anyone can make their own repo is the fundamental strength of flatpak as opposed to snaps; it's not tied to one organisation, Flathub is the de facto central repo but it doesn't always have to be.

What's ICE, that's a difficult acronym to search?

But the difference is we all have a choice of an email provider, whereas people are socially expected to have a smartphone these days and those are pretty much the two viable choices.

Apart from the CEO, I've been a bit concerned with the number of outages recently with quite poor and inconsistent communication or updates - not especially long outages but made much more stressful. There's something really off about the way they communicate things I've found. So that combined with the idiot CEO has made me start the process of moving away from Proton, I don't trust them any more.

I think the best strategy is to spread thinly, don't become reliant on any one provider.

I second this. Not wanting to shoot down your idea, quite a big deciding factor for me is the release cycle and update process and you won't experience that in a week. Might be a good idea to list what you've already tried though.