There's still no widely accepted answer for what 'properly package their apps' looks like. You could want snaps or appimages or a flatpak, or rpms or debs or docker containers or nix flakes or cargo crates or python virtual environments or jars or javawebstarts or portable windows executables or windows msis or webasm packages or web pages ... there's an impossible profusion that it's currently unreasonable to expect devs (many of whom are working for free) to support more than a couple of.

If there were a single solution that worked in almost all cases and platforms, didn't put unreasonable constraints on packagers and was widely adopted, then it might be somewhat reasonable to expect devs to support it, but that's far from the world we live in. The closest to that (despite its real problems) is probably piping a curl to a bash script...