This will help eliminate excess baggage that builds up over time by automatically removing end-of-life runtimes that are no longer used. As the system is updated to use new drivers/run-times, the old ones can be automatically removed.
This might solve the issue with flatpak nvidia driver versions not being removed and accumulating over time. AMD/Intel don't have this issue as a single flatpak mesa driver version can work with multiple system drivers. Nvidia's closed source driver needs an exact version match to allow for flatpak's sandboxed GUI apps to work.
At least that's how I understand it, take it with a grain of salt.