Why would you control for quality advancements when the question is if people are better off today than in the past? Having access to the entirety of the world's information is nice! Imagine saying 'living today is better than living in the Middle Ages' and have someone say once you controlled for technological improvement it wasn't. It either is or it isn't.
Regardless, even if you try to stick to common things like cars, houses, etc. our houses are way bigger now than they were back then, we have more cars per household and they don't constantly break, etc., etc.