In theory Flatpak allows for sharing of dependencies and has sandboxing built in. This comes at the cost of needing special tooling, a repo, and non-portable (portable here meaning you can put the files wherever you want) applications. In practice you're probably better off using Firejail or the like on AppImage if you want the sandboxing anyway, because of things like the issues noted in the article. Snap is like Flatpak but even worse because it is entirely controlled by canonical.

Anarchy. Steve Jobs / Tike Cook can declare one package format for Mac. No one can do that for Linux. With a single distro leadership can sometimes do it, but there isn't enough funding to solve problems within a single distro.