This isn’t a FOSS apps list but a Free (as free beer) software list for Windows with a bunch of cool FOSS apps https://alternativeto.net/list/29653/my-windows-setup/

I’de rather go with Linux Mint Cinnamon or Nobara with their custom GNOME DE

I think you confuse security and privacy. Samsung are pretty secure from what I saw. They are not private at all however. You can debloat it with adb and maybe tools such as Universal Android Debloater.

There is a couple of guide such as this one: https://linustechtips.com/topic/1402380-ultimate-samsung-oneui-debloat-privacy-customization-guide/

I wish I discovered that sooner thanks you. Except a few games they all have good artwork, etc…

FlatPak is not the as secure as everyone think it is.