Iran Unveils Its First-Ever Domestically-Built Fighter Jet

No. I know these fighters from the Brazilian air force. It's an F-5. They probably are able to manufacture parts for them, but it's most certainly not an original design.

There is a good incentive to make parts for them and to, eventually, be able to build the complete plane themselves because they have quite a few F-5's and they are reasonably effective against their regional rivals. If they managed to get reasonably modern avionics and weapons in these, they could defend Iranian territory quite well. A lot of military pilots trained on its brother, the T-38.

Lower speed and worse maneuverability make no difference if they can lock a missile on you before you can do the same to them.