As beneficial as it would be for Radeon RX 7000 owners (RDNA 3), the significant advantage for AMD lies in PC gaming handhelds and RDNA 3/3.5 laptops. IE, the devices that are currently shipping and won't get upgraded RDNA 4/5 versions anytime soon.
AMD's handhelds would be so much better with FSR 4 support. As a frequent Steam Deck user, this would tempt me upgrade to a newer device with RDNA 3.5 graphics.