Used to be both, but every game I've purchased this year has been played which is how I'm going to collect moving forward.
I get where this question is coming from but why does everyone shit on gamers who do buy games just to admire them on a shelf? If you collect stamps or coins you don't use those, or if you buy a 20k piece of art and hang it on the wall you aren't really "using" it either. To me, actually using the game is a perk of owning something special.
Society has taught us that people buying a car which depreciates in value the moment they drive it away from a lot and then owe money on it for five years is normal, but a person who collects video games and keeps them sealed is some sort of weirdo.
I know gaming isn't an investment, but there are much more foolish things to spend money on honestly. I know people who blow through money on alcohol, weed, restaurants, TV cable bills and car payments and think it's justified but raise eyebrows and think people who buy games to keep them sealed are idiots.