Alright, trying it. I don’t use Flatpak for anything else because of updating, but Steam updates itself anyway so that shouldn’t be a factor.

EDIT: I forgot dependencies are a bit rough (almost 2GiB total) because sandboxing, so that might’ve been a bigger factor before

Re-installing worked, so I am not sure what happened with the dependency solver (hopefully this doesn’t happen again soon). Though I am almost to the point Steam wouldn’t be such a big loss especially if I can still play a few DRM-free games already downloaded.