You’d be surprised just how much dust a computer can collect. Particularly some computers with their big system fans and multiple other fans for the CPU and graphics card. Sometimes so much dust can accumulate, that key components of your computer will stop working and your computer may shut down to avoid overheating.
So it makes sense every few months or so to check inside your computer and clear out any dust that may have gathered there. Particularly if your computer lives in a dusty environment such as a basement or garage.