If your build instructions are "zig build" then that works for everyone, on every platform: Windows, macOS, Linux (all distros!), FreeBSD, etc., and it works for all versions of them.
That just make no sense, and it is insane that this is the standard way of doing things.
In current day, everyone wants their own package manager, and compiled builds to have no dependencies. While this makes distribution and building easier, it makes it impossible for distro maintainers to integrate it properly into their ecosystem, apply fixes and upgrade libraries across swathes of programs. I don't get why people can't accomodate for distro packaging in their tooling as well - many languages like python handle this just fine.
I believe we'll end up at a point where the system package manager will mean nothing - it'll manage end-user programs, which will all bundle their own versions of libraries - even ones considered "system" like libc and libX11. No sharing of (security) fixes and feature upgrades, and you'll have to learn a new package manager each time you switch languages or sometimes even projects...
Makes it indeed easier to build, deploy and sell software, compared to the former world of one big distribution where thousands of software packages were designed to work together.
I do believe the driving force in this trend is not coming from the users but from the producers desire to assert property of the software. Think the enclosure trend, for software.
"App store" is having a centralized distro repository where you get all applications from (e.g. Windows Store), and "merely a collection of independent applications with no relationship with each other" is exactly the opposite (e.g. that's how the Windows apps were distributed before the advent of Windows Store).