seriously... S / M / L why does everything have to be a branding/marketing exercise?

I wondered the same as a kid about cars, maker - model - variant would just be nice if it was consistent.

Anyways when a new model is released they want to have some interest and hopefully some tyre kickers will stick and hoping some social medial coverage

then they can do XL 2xl 3xl when they want to go further

large, gigantic, and humongous - like NASA toilet gear