The air spray cans aren’t perfect, but its better than nothing at all. Also, in some laptops the fans are quite difficult to get to, and people don’t usually want to have to buy/reapply thermal paste. Like the fan on the gpu of my old laptop could not be taken apart easily at all… I could get it out, but I could not clean it effectively with anything because you couldn’t get to the blades without taking fan apart. Paper towels moved the chunks further in, and the air can pushed them the rest of the way out.
but yeah, most fans are pretty easy to get to and clean. and the air compressor worked wonders for sure, but actually the uber high pressure and subsequent high rpms broke one of the fans.
From my experience, laptops are far more delicate than your making them sound. I’ve watched 3 friends take apart several laptops for various reasons, and took apart my own a bunch of times (none of which were macs, I have little experience with them). most of my friends, who were definitely technically inclined and computer knowledgeable, incurred more problems after taking apart theirs. On my laptop, when I was trying to replace the keyboard, the bracket that secured the keyboard connection just broke off through no fault of mine. poof, no more keyboard. laptop parts are delicate, ive seen a lot of them break. theres always a chance you could drop a screw in between something and not get it back out, or other things. Anyway, my point is laptops are expensive, and while I encourage fixing it yourself instead of taking it somewhere, I’m saying be very careful with your investment.
And make sure you take out your battery before opening your laptop.