The future will be made up of a mix of manned and unmanned platforms, working together. In the unmanned department, Iran has made good progress. When it comes to fighter jets, most of Iran's jets are far too old and need to be replaced soon.
If facing an adversary like the US, Iran has no chance of attaining air supremacy. That's when it's missiles work as more of a deterrent than anything.
If facing a regional rival, then a large number of drones along with an airforce made up of 100+ 4th generation fighters is fine. Iranian pilots are very well trained and if they have good hardware, add to that Iran's air defense/missile capability and it's more than enough to deal with any regional threat.
Iran has messed around with a few various designs in the last 2 decades but we have never seen any serial production other than reverse engineered F-5s on a small scale. But F-5s can only supplement the airforce.
I can't blame Iran for not committing to projects like Shafaq or Qaher. Qaher for example, it's far too small to carry any serious payload. Compare the size of Qaher to the new Russian Checkmate ,which is considered a small stealth jet. It's literally huge compared to the Qaher.
The Shafaq, I'm guessing they conducted various tests and determined that it just wouldn't be good enough compared to what's out there.
Realistically Iran is probably going to diversity and purchase some jets from China, some from Russia. The Chinese have offered Iran the JF-17 but Iran is not interested. The J-10 is China's more capable export fighter. I've read that Iran is interested in purchasing 35 of those as a preliminary deal, maybe followed by another batch afterwards.
The issue is that China wants foreign currency reserves, while Iran wants to exchange oil for the fighters. However the situation in Taiwan, with the US arming Taiwan to the teeth has greatly angered China. That increases the likelihood of China selling Iran the J-10s just to piss off the US.
The Russian option is a SU-27 variant, probably the SU-30. Iran has been interested in this purchase for a while but Iran is playing it smart. Iran is showing that it is in no hurry to purchase the jets. Russia is low on funding for their own weapon systems and would hate to see Iran purchase Chinese jets rather than Russian.
However by not reaching towards Russia and then buying Chinese first, this will work in Iran's favor because it will most likely motivate the Russians to give Iran a more competitive deal on the SU-30s.
In the end by buying some Chinese and some Russian, Iran will benefit by not being dependent on any one side for its airforce. For whatever reason, if one side decides not to sell Iran parts or their foreign policy suddenly sours towards Iran, then Iran another option just sitting there.
Also by purchasing from both China and Russia, Iran will get exposure to both Chinese and Russian technology, which is better than only having exposure to one side.
Again we know that Russia desperately needs funding for their future weapons systems. Either the SU-57 or Checkmate would be a good 5th generation option for Iran imo, if Iran doesn't produce something by then.
Realistically designing a 5th generation fighter is not that difficult. Lots of nations have done it. However as we've seen only a handful of nations have been able to actually build 5th generation fighters.
I'm not sure if Iran will get its hands on a 5th gen fighter until at least 2030's. That might even be a better option realistically because by then the technology will be more mature and cheaper.
If Iran purchases from either China or Russia, we will probably see some sort of joint production deal along with vital technology transfers. The thing about Iranian leadership is that they're thinking long term. They're not concerned with investing in something flashy, but rather in something functional.
