I used to help direct tournaments, including the US Chess Championship. The number of draws is pretty amazing, and part of it is the level of competition. They get material reduced to a certain point and position, realize that neither player is likely to make a catastrophic mistake, and offer a draw. I watched Josh Waitzkin and Boris Gulko battle it out to a closed position where they had lots of movement available, but neither could get a decisive advantage without a blunder, and that just wasn't going to happen. They drew, then went back to the break room to replay the game and see if there was a way around it.
And then there's a certain player who would offer a quick draw then go to the nearest casino to play poker, which he was quite good at and normally won more than the tournament would have produced. And still get his appearance fee for the tournament.