Stock Android

Would it not be better if Google update android through the play store so that anyone regardless of the handset maker can download instead of waiting for the handset makers to decide when they roll out their customized versions. One should be free to either apply the UI of the handset maker anytime they choose. I am just musing but if its already existing without rooting then somebody could do me a favor by pointing me in the right direction. I have done a bit of googling but have hit a dead end.