Also very limited range and payload. The MiG-21’s combat radius is only about half of an F-16, and it’s combat payload is about 1/3 of that of an F-16. I think the author mistakes number of units produced for quality of the design. The Soviet Union also produced about 20,000,000 Lada automobiles — I wouldn’t say that speaks to the excellence of the design either, but rather to Soviet central planning.