Iranians are extremely upset with the way how Iran responded against Israel throughout the conflict so far, even as far as stating that investing missiles over aircrafts shouldn't have been a thing in the first place.
These people are dumb. The Iranian missiles are the only thing their military had which worked properly. Without the missiles being able to destroy Israel without much chance of interception, with impunity, you would be seeing no ceasefire at all.
Iranian aircraft would have never been able to even reach Israel for counter strikes with the US and NATO covering them. Just see how few of the Shahed drones even reach Israel.
There is also no way Iran can have a larger air force than the US and its allies. Not financially possible. Even China is hard pressed to achieve this.
Would you rather have a single Su-57 fighter for 50 million USD or a hundred Emad rockets for 500 thousand each? Plus unlike the aircraft they can produce the Emad themselves.
While Iran needs to modernize its air force, it needs to be used to plug gaps in IADS coverage.
IMHO the major Iranian issue is their lack of robust encrypted military communications, lack of IADS integration, and lousy intelligence and counter-intelligence.