Aren't the root authorities in browsers/OSes just a means of short cutting the chain of trust validation by eliminating the need to validate the chain up to a s

Aren't the root authorities in browsers/OSes just a means of short cutting the chain of trust validation by eliminating the need to validate the chain up to a single root? I share your frustration and I understand that trying manage levels of trust a tough problem compounded by the fact that a user's expectations are fluid.