yep. in 2 dimensions, nobody really debates on whether x or y should point up, so i kinda think the debate about z stems from whether one thinks we should put the xy plane horizontally (like a sheet of paper on a desk), or vertically (like a chalkboard).

does any software default to making x be the vertical axis?

Smh I was fine with both. The upper one reminded me of the X Y axis we use to represent functions in maths. While the lower one represents altitude on a 3D map.

Good answer. Many posts are people saying "my approach is the right one, other people are irredeemable morons who should burn in hell", but you're right, it depends on your perspective.

Invert y axis is the first option I tick in every game