Isn’t that just a convention of various 3D applications?
To me, Z was always UP and XY were the flat 2D horizontal plane, at least from a 3D modelling point of view.
But when looking at the screen as a projection to the viewer, I guess Z would be the “depth.” so that Z-buffer depth term makes sense.
Either way, I don’t think axes will change as it would mess things up with importing assets among other things.