For exclusives PSP wins in a complete blowout and it's not remotely close. PSP is a top 3 system ever period imo.
I still love the Vita for having many good PS2-era ports (MGS, FFX, Sly, God of War, Rachet, Odin Sphere, Ninja Gaiden, etc...), the best MonHun genre games, most of the best indies of the past decade pre-Switch, and a litany of Falcom greatness along with much much more. Being an exclusively portable gamer, the Vita was my console of choice last gen and I still play it regularly. It also introduced me to genres like visual novels.
Still overall counting ports PSP wins too but not by as much. The litany of classic game collections on PSP (especially Sega and SNK) were a huge boon to a relatively poor me back in high school and college. Beyond that it is the GOAT system for SRPGs by a mile. It also has (uniquely for a portable) a large amount of great western developed games like Pursuit Force and GTA. Ultimately PSP has a really deep library, there is a reason I have more PSP physical games than any other system (although Vita is third).