Grapheneos, ios, or macos, unless it’s a money thing, over desktop Linux. These do what you want much better than desktop linux and will provide more protection against targetted attacks. I think macos is most like what you want and you can exclusively install open source programs if you want.
Hold up, you already made this thread:
My advice is the same as it was in that thread. You can do this on mobile besides maybe Libreoffice, but you can use proton docs and sheets to write documents. Macos is also an option for desktop.
If you go with desktop Linux anyway, Ubuntu or Fedora. Ubuntu has the most resources and support but has slower updates, but they patch the type of vulnerabilities that were in the news quickly. If you want to minimize time in the terminal or configuring settings it’s the safest bet.