Where do you store where the application-specific KV stores are located? Are you just going to hard-code it so the application cannot be moved or installed elsewhere or on external drives? Where does the OS store its own settings?
There are a lot of problems with software "shotgunning" their junk across the system. This isn't exclusive to the Registry or even a specific OS unfortunately. Just go look at what configuration files are located between applications on Linux for example, it is not consistent at all.
Linux is about as consistent as Windows these days. /etc isn’t really a “dumping ground” for everything and is quite static now. Just diffed a snapshot of /etc on my workstation from a month ago and there aren’t really any changes I didn’t put there myself. It’s reasonable to make /etc immutable on a lot of systems; something impossible with the registry.
Home is a bit more chaotic but most applications follow the XDG specs. Mostly. Less so with cache and state files (vscode, for example, dumps tons of cache/state files in .config instead of .cache and .local/state). And weird things like Flatpak shoving everything in .var.
I’d say things generally behave about as well as windows apps which often treat documents as a dumping ground for all kinds of files. I always have to go to pcgamingwiki to find game data locations without having to check half a dozen places.
For administration I really like the /usr and /etc divide. Vendor files go on /usr, and overrides for the running system in /etc. It’s useful to be able to peek in /usr to see defaults.You don’t really get that ability with the registry. With some more modern setups /etc is bootstrapped from /usr (for example, with systemd-tmpfiles) and you can “factory reset” a system by clearing out /etc (with some asterisks around restoring state for a few of the legacy state files still kept in /etc if the system is has manually created users/groups).
>Where do you store where the application-specific KV stores are located? Are you just going to hard-code it so the application cannot be moved or installed elsewhere or on external drives?
I would put that in the same directory as the executable so I can have more than one executable of the same program or the path is simply passed as a command line parameter in the systems unit file.
Compare that to hardcoding the registry key path in the executable...
Which is how it works in Windows, if you follow Microsoft's own (admittedly confusing) guidelines. Every user has directories for both private and user-visible data, as well as for some half-thought-out feature called "roaming" that I've personally never seen an actual requirement for.
Storing .INI files in the .EXE's directory has been a no-no for many years, and nobody should be arguing for that. But the central registry concept makes even less sense. Use .INIs in your format of choice, and store them in the appropriate user-specific application data folder. Additionally, they should be created when the executable finds them missing, not by the installer.
The latter practice alone solves a multitude of problems, ranging from multiuser support ("Whaddya mean, install for everybody who uses the computer or just me? WTF?" -- your users) to the issue of requiring admin rights at installation time that are not really needed by the program itself.
macOS has a folder called Library where this stuff is supposed to go. It's not enforced by decree, with many apps doing their own horrible thing. Ultimately, its macOS' culture that mostly makes apps puts their settings and other resident details in Library.
I'm not knowledgeable enough to know why a culturally enforced folder is far worse than the database that Windows has. Care to enlighten me?
Linux has ~/.local, ~/.config, and ~/.cache for user-specific program files. Sadly many programs don't respect these and pollute your home directory instead.
Even better are the programs which will stick cache files inside something like ~/.config/appx/mycache . Like a little middle finger from the developer to waste space in my backups.
macOS also has NSUserDefaults which is a similar application (but sometimes developer team?) scoped KV system which is actually just a plist file shoved into ~/Library/Preferences. It's the most similar thing to the Windows Registry in both its intended purpose (small amounts of configuration data) and the ways people abuse it due to its simple interface (storing absolutely everything in it).
There are a lot of problems with software "shotgunning" their junk across the system. This isn't exclusive to the Registry or even a specific OS unfortunately. Just go look at what configuration files are located between applications on Linux for example, it is not consistent at all.