I believe the same SW version is packaged. Nvidia said they'd drop support in the 580 release, but they shifted it to 590 now.
The arch issues are another layer of headache by the maintainers changing the package names and people breaking their systems on update when a non-compatible version is pulled replacing the one with still pascal support in it.
According to the Steam HW survey around 6% of users are still using Pascal (10xx) GPUs. That's about 8.4 million GPUs losing proprietary driver support. What a waste.
Making them open to contributions was the first step, but ok I won't engage in this petty tribalism.
The topic was about nvidia's closed source drives.
Valve couldn't do the same for pascal GPUs. Nobody but nvidia has the reclocking firmware, so even the reverse engineered nouveau NVK drivers are stuck at boot clock speeds.
RAM is the last component you should OC, it is arkane wizardry compared to CPU and GPU overclocking. Even a seemingly stable memory OC can crash at different workloads and when it does it gives seemingly unrelated errors that sends you down in endless rabbit holes.
Rolling distros also only update when you tell them. It is the user who is pulling the trigger on the footgun in both cases.
I'd say the main difference is that arch users are more trigger-happy about being up to date.
Also, I think pacman should at least warn you if the problem is enough to warrant a post on the arch website.