What's so good about the Chase Trifecta?

Hi I hear a lot about the Chase Trifecta consisting of CSR/CSP, CFF, and CFU. My question is, why have BOTH Chase Freedoms? From what I see, CFF has the 5% rotating category and the CFU has that 1.5% CB on all other purchases (CFF 1%), but besides that there is a lot of overlap. Can't a better trifecta be made with just 1 Chase Freedom card instead of 2, with the 3rd card being some other better Chase cc?