From what air force experts at RUSI say, especially Justin Bronk, the biggest issue with the F16 is that it has delicate landing gear that were made out of aluminum to save weight. That's fine for pristine airfields that the US and NATO rely on but the Ukrainians are using anything they can, including roads, for take off and landing, due to long range strikes on existing airfields that crater the runways.

That's why they recommend either the F18 or Saab Grippen, which have much sturdier landing gear that'll work for the dispersed airfield way the Ukrainians are doing things, which won't change because as soon as Ukraine spends the money, resources and time to upgrade airfields then Russia is going to hit them to at least delay their use.

The problem with F18 is there aren't many that are free to give away that are in good condition. And with the Grippen, Sweden might be apprehensive due to escalation risk.