On overclocked machines you see this a lot. The owners usually counter "it worked like this for years." The problem is that parts age. Now they may be thinking about silicon chips which mostly don't age so fast but the parts that do in just months are electrolytic capacitors. To fix this we swap out the motherboard and PSU so they can get their overclocking fix again.

I read nothing about other changes so the factors of drivers are dismissed since same drivers would load on a reboot.

Classic aging signs to me.