Stability and standardisation within the kernel for kernel modules. There are plenty of commercial products that use proprietary kernel modules that basically only work on a very specific kernel version, preventing upgrades.
Or they could just open source and inline their garbage kernel modules…
I guess we can formulate a law:
Pick any two.
Look, this is the reason people pay RedHat money. Go install Rocky Linux, turn on all the automatic updates and ignore it for the next five years.
On the enthusiast side, NixOS seems to be working fine if you want newer versions of software or larger repos.
Used to? It’s standard practice like everywhere.
It mostly affects people working with ”fun” enterprise hardware or special purpose things.
But to take one example, proprietary drivers for high performance network cards, most likely from Nvidia.