That's not what i asked, why do you trust a no name dev more then the distro your kernel is coming from? And do you really think flatpack prevents you from running packed malware?
Why do you assume the flatpak comes from a no name dev? My calculator flatpak comes from the same people who wrote it, and I obviously trust them, otherwise I wouldn't be using their application.
So why should I trust them less than my distribution?
With my calculator flatpak I only have to trust one person and to a much lesser degree, because they declared that the calculator can't access my personal files to begin with. The same app in my distribution repository has full read-write access to all my users files, network access and much more. So yeah, I trust it more.
Distribution maintainers are nothing but a middle man, which don't even audit the code they package, so there's nothing I gain from them.