It would be nice to have something like a fusion of conda and apt to work right out of the box on distros like Ubuntu. Like an "apt install --user". I don't understand why we need root rights to install programs that will not need root rights to run anyway. Seems like a huge and obvious oversight to me. I guess it's not a big pain point because in most cases people use their own machines and have root access. Not always the case though in companies or university labs for example.
I have been wondering this for ages. Just last week I had to manually set up KeePass, VSCode, IntelliJ, Guitar (git ui) by manually unpacking tarballs (luckily already built) into ~/bin. Guitar luckily had an AppImage which worked beautifully as a single executable.
For that reason alone I'm a huge fan of AppImage above snaps and flatpaks.