Yes this is kinda how apps work on macOS, but not all apps yet. The new sandboxed container model isn't mandatory yet. Some apps are just a folder of files with no kind of containerisation at all (other than the .app itself being a folder rather than a file). More modern apps store all their data in a containerised filesystem though.
It leads to some cool things you can do like easily capturing the icon of an app or even changing it without having to change the app itself.
But on the self-hosting side, docker is making big strides there. Almost everyone deploying something like Home Assistant for example will do it through a tree of managed docker containers, in many cases without even knowing it :) It comes with a supervisor (which is also dockerised) which manages that part very well.
I think most consumers I know keep their computers for long enough by the way.. Phones come and go, but desktops and even laptops tend to stick around until they do break and I can't fix them anymore or just heave a sigh and go like "NO this time you really have to get a new one, Windows Vista hasn't been supported for years"