Quality generally with many manufactured goods. There are health and safety regulations but if there were a requirement for a 20-year warranty (which is about what my Aeron chair has) both quality and prices would probably increase significantly.

In the opposite direction, you're not actually allowed to generally buy a car without modern safety features. (Although automakers do make cars that are have higher or lower safety ratings within the regulatory framework.)

A common thread is that when push comes to shove, a lot of consumers will choose the lower price.