I am not a tech person, but I cleaned out my secondhand PC today, and it took hours with the sheer amount of dust accumulation. The fans were nearly overloaded with it!!
Does a clean PC run better / faster than one filled with dust? Or is it more a matter of keeping the fans running easily? Or something else…? Idk, maybe I imagined it, but it seemed to boot much faster after cleaning. Could be wishful thinking!
Computers need to be relatively cool to function properly.
Dust acts as a heat insulator, trapping heat inside.
Dust also clogs the cooling fans from doing their job.
Most computers have built-in features that auto throttle or even self shut-down if the heat gets too high.
More dust = more heat = more speed throttling & shutdowns.