History will show the F-16 to probably be the most successful manned jet fighter made... a combination of capability, maintainability, and cost.
It'll be in tough competition with the MiG-21 for that honor. It's not numbers alone, it's the platform taken as a whole.
They'll be flying probably well into 2030's and maybe beyond. Kind of like the B-52 with a service life of 60+ years. That's like seeing Sopwith Camels fighting in the Vietnam war.
Had political considerations not come into the selection for the F-XX project.. it would have lived on even further in the guise of a XL as the E model.