At the lowest level you have the kernels (KDE and Gnome both run on Linux AND BSD) which may or may not have drivers built in. Then comes the distributions which are opinionated in the kernel versions, packages and patches they add.

Some of those packages are desktop environments or window managers and they are opinionated in how they run other packages and their lifecycle. Some full featured others are tiling. Some of them run on both Xorg and Wayland.

Last we have the actual packages, and they need to work in all these different environments, sizes and lately different protocols. They need to support different drivers, permissions and file system hierarchies. They do this by relying on each other, a package handling video focuses on supporting video and sound drivers so other packages can import that package.

KDE might have a very polished and up to date settings panel, checking for all drivers and their features. But in reality it works as intended on Ubuntu, but Debian is behind and doesn't want to patch the drivers because stability, on Arch there was a regression and most of the BSDs don't even support the driver. And one time Linus came along and didn't listen to the warnings and fucked it all with one line.

Nobody controls all of these pieces and they're so spread apart that what might seem as simple as a panel for printer settings quickly gets very complicated. But I wouldn't have it any other way. For those who want the one size fits all there are already options.