I don't clean my computer with compressed air, I use a dry paint brush with some gentle hoovering, holding any fans down while I do so they don't spin too fast buggering up a bearing.
I clean the external filters every month and do a full clean when ever it is too dusty for my liking. Which is around the 6 month mark.
Yes, regular cleaning may well help longevity, but you don't have to do it, like, all the time.