I usually go Flatpak > system package (rpm) > AppImage > direct download. But it also depends on what I need.Flatpak usually gives the latest version and is nicely integrated with everything.System packages are usually outdated but use less disk space.I only use AppImages if that's the only way I can get the version I need. I also have it integrated with appimaged.Directly downloading a tar.gz or similar I try to avoid as much as possible because it isn't integrated with anything.
I actually put my grandma on Zorin OS and, well, what happened is that she is using her PC less now lol. But she can get stuff done usually.(Get stuff done == read emails, read news, print documents)
I usually go Flatpak > system package (rpm) > AppImage > direct download. But it also depends on what I need.