The idea that the Olympics are an amateur event is in general a myth. A lot of the sports absolutely have access to better training facilities, have more funding, and better sponsorship deals than everyone in the UFC bar maybe a couple. Some countries even have elite training programs from childhood for their chosen sports. The UFC doesn't have anywhere near the same level of talent that you'd get in some of these sports, and since their fighters are essentially independent, they can't finance the same quality of training programs the Olympians receive (you won't find many Dolce's in Olympic training programs for example). One day hopefully but, not now that's for sure.