You climb a mountain because it's there. Different people have different mountains. It's an interesting challenge, you can improve it or make it do X,Y,Z, you

You climb a mountain because it's there. Different people have different mountains. It's an interesting challenge, you can improve it or make it do X,Y,Z, you can add speedrunning or competition gaming features, solving puzzles gives a sense of accomplishment, a certain small group gives you social clout, etc.