Also depends on your environment.
The computer in that youtube video is fairly clean, not much build-up removed. Also his computer case has filters, that keep the graphics card very clean in the first place.
But if you have pets, or smokers, or some other kind of dusty environment, and your computer case does not have filters, then your video card can be extra dirty.
If that's the case, and it's been over a year since your last cleaning (or never), then you should consider removing the fan/shroud from the video card to fully expose the heatsink, and then get the built-up gunk out from between the fins of the heatsink. The worst case I ever saw was a video card with a blower-style cooler (where the video card exhausts all the air out the back) whose heatsink fins were fully encrusted by bird (cockatoo) feathers that were hidden under the shroud and not visible until you removed the shroud (the immediate fan area looked clean).