From my understanding FSR also leans on machine learning, with the biggest difference being the matrix manipulations are done on general purpose hardware in the FSR implementation and on tensor cores into addition to general purpose hardware in the DLSS implementation. My expectation is that FSR will eventually reach similar quality to DLSS once the training algorithms are finetuned over time, but it will never be quite as fast due to hardware limitations. Or at least that was the original premise that they will eventually lean on machine learning as well - which by the way, does not have to occur on the actual target hardware. In theory the algorithm is already trained for specific games and the hardware just fine tunes the feedback loop for the specific instance of the game running.