Honestly I run both a regular and immutable fedora on 2 different laptops and I wouldn't say it is "a game changer". There are pros and cons of both systems, but under most usage I haven't found a difference that I would call game changing. App installation and update is different, starting flatpak and toolbox installed apps from the terminal is different, your homedir is somewhere else...and that's it?

And while I have enabled the flathub repo, to have more choice over the limited but curated fedora repo, I am a bit wary of the flathub ecosystem as it:

- includes proprietary stuff - a lot of "community build" flatpaks for which it is not obvious in a quick glance who build it exactly? - I don't think the flathub packages are analysed for malwares?

I could see flatpak becoming a source of malware. Sure most flatpaks are setup to be sandboxed and you can fine tune sandboxing but most people would not know about it and a lot of flatpak already have access to your files otherwise they are not usable.