Are hotels dependent on Third Party Wholesalers?

By Third Party wholesalers, I am referring to Expedia, hotels.com, orbitz, priceline, etc. All of these sites claim to offer discounted hotel rooms. The truth is, all franchises offer lowest rate guarantee on their own websites. Thus, all rates are supposed to be in parity-no website has the edge over others in terms of rates is concerned. Then why do most people use third party websites to book hotel rooms rather than going to the Franchise website if they offer the same rate? Third party websites take an average of 20% of the rate as their fee, in other words, the hotel loses out on 20% on room revenue every time an consumer elects to book from an third party website. Franchises get a lot of royalty ( a lot!) from franchisees, and are still not able to market enough for the consumer to purchase rooms through the main hotel website. I see a very viable solution to this. Consumers go to third party sites so that they can see multiple hotels at a time, and choose within that site, rather than going to each individual hotel website, saving valuable time. If a company like Progressive insurance saw this, and implemented rates of all its major competitors on its site to bring traffic straight to them, why don't hotel franchises? People who are only looking for hotel rooms should be coming straight the the hotel website, and be given the luxury of comparing rates as they do on third party websites. If only all franchise owners joined hands and pressured their well paid franchises, we could see this happening. And soon, third party websites will have to look elsewhere to find business.