because the package build script isn’t available?
What are you talking about? Every Flatpak on Flathub has their build manifest available on GitHub, you can fork or download it for yourself and change it how you’d like, just like you can with an Arch PKGBUILD
And the problem still isn’t solved because now the people who can set bad defaults still exist, they’re just different people.
For one, unlike with distro packages, lots of Flatpaks are made by the developers of their apps, so bad defaults aren’t really going to be a thing for those since the developer would want to choose what’s best for their own app
And for packages maintained by a third party, bad defaults are less common because maintainers don’t need to account for each individual distro’s unique package situation or specific dependency versions, and only have to package it once for every distro
Man, it really sucks to find out that even on this site, there’s still people who get upvotes for saying that people like me are something to be “cured”