

Don’t knock it till you’ve tried it. History has shown that a system package manager is a very poor solution for distributing software. Anyone who disagrees has never been involved in shipping and/or supporting software on Linux. Nix tries to solve this one way, immutable distros solve it another (IMO much simpler) way.
You can still install software using a traditional package manager via podman or docker. Toolbox and Distrobox streamline this for the common shell use-case by automatically doing things like mounting your home directory, using host networking, etc so it looks/acts like a regular shell. Anything you install in the container works exactly as it would on the host, except you can completely wreck it without breaking your host (just don’t rm -rf your home directory, or anything shared)
Immutability is the future of the Linux desktop.
I’m not trying to pick a fight or anything, just doing my part to prevent the spread of disinformation and ignorance on the internet. The second paragraph in your comment shows you don’t understand these technologies at all, and I feel compelled to point it out for the benefit of people reading it, so they don’t come away misinformed.
There are no abstractions here. Containers use kernel features called “namespaces” and “cgroups” to isolate system resources and implement sand boxing. There’s no abstraction layer in the software engineering sense. You might be confused because containers look like virtual machines (which is by design), but they’re not that at all, they’re regular native system processes that just aren’t allowed to see each other. There’s nothing about this that is precluded by “cobbled together e-waste”, except maybe if you can’t install a modern-ish Linux kernel for some reason.
For some perspective, the exact same containerization technology is deployed in production on millions of Linux servers around the world every day. Every wasted second in those environment costs money, and they wouldn’t be used if they were “wasteful” or inefficient.
There’s a lot of misinfo online about Flatpaks and their disk usage. Yes, they include all their dependencies, but so do a lot of other devs who ship software on Linux (and some don’t even bother to statically link them) outside of a system package manager. The name for that is “vendored” libraries. Flatpaks however implement deduplication.
For anyone on the fence who is reading this, some important perspective to have is that, like many old communities, Linux has people who are stubborn/resistant to change. Sometimes that’s a good polocy, sometimes it’s not. In this case, it certainly is not. Look at the growing success of immutable distros (like Steam OS) for proof of that. Android and iOS have successfully deployed a similar model since day one. Linux can’t offer a stable API like win32 for various reasons, but it can do Flatpaks, which comes with the added benefit of secure sandboxing (which win32 lacks). It makes life easier for users, and makes it easier for devs to port their software to Linux.
It is the future.