Why would they intentionally make it difficult to compare prices when travel agents and price comparison sites make it easy? I am pretty sure AA thinks that their website is the easiest way to book AA flights. If you disagree, you can get the same fares elsewhere trivially.
The "search by price and schedule" feature makes it easy to see what options you have on AA if you choose to go that route. Without even clicking anything, you can see the effects of leaving on a different day, choosing a different fare class, or taking a connecting flight versus flying nonstop. This makes it pretty easy to compare. (It is arguable that there are too many options. But this is becuase air travel is expensive by default, and people want cheap. So there are a lot of "discounted" fares around. If you don't want hassle, pick "search by schedule" for the search type, and "economy without restrictions" for the fare type. You will have your ticket in seconds, won't have to pay for checked bags, will have the option of paying $50 to upgrade to first class, and can cancel or change the ticket at any time with no fee. The only downside is that the ticket will cost 10x as much.)