Z-up is really only common among architectural or engineering type software. CAD and other types of software, for example.

Y-up is common among basically all other types of software. DirectX API is Y-up, for example. Which means anything that interacts with DirectX that has Z-up needs to convert the axes first before doing its calculation (a literal nothing cost microoptimization, but could be big depending on the software and platform).

It's probably fine to leave as is in the long run, but its just annoying to me that I need to convert between the axes in Blender export settings, and would be more convenient if all the software I use used the same system, which is now Y-up. Blender is literally the only one. Honestly, I agree that it should be a user setting in Preferences, but I dont know if Blender is programmed to handle this or if it would need to be entirely rewritten.