Who’d pay to restore a MiG 21 - except, perhaps a collector of antique planes?
If you ain't got any jets in your air force, as the Iraqis don't, I guess these are better than nothing. Not much better, but better.
The Mig-21 was probably the most common Iraqi fighter and the one most pilots and technicians are still familiar with. Not to forget that you have plenty of upgrade packages available. Cost effective while they wait for their new F-16s.