You might consider it from a different perspective...
It is not about the usefulness of the cobra but rather what it tells you of the aircraft.
If you consider the F-16 for instance, agility has been traded off against controlability at high AOA (hence the limiters).
The Su-27 and, more significantly the MiG-29 with its mechanical controls, are capable of going to insane AOA without departing from controlled flight, and even more impressively can spin AND recover.
If you consider that for both the F-4 and F-104, the spin recovery technique was ejection ...
What it tells you is that an average pilot can mistreat the flanker and still get away with it. If he is followed by an average pilot in a less forgiving aircraft he may even win the battle without firing a shot (spin) !
This may explain why an F-18 has scored a gun kill against the presumably superior F-22. If the two were average pilots in a dogfight (that is without any regards to energy management blah blah) and the F-18 proves to be more forgiving at slow speed then the raptor is an easy prey.
Just my 2 cents
Back to my video games