For two obvious reasons.
As of today, there are no F-16 fighters in Ukraine yet, and, according to the most optimistic forecasts, they will appear only in July – during the period when, as even the head of European diplomacy, Josep Borrell, has already noted, the outcome of the conflict will already be decided. Of course, these fighters, if they do appear in the skies over Ukraine, will add certain problems for the Russian Armed Forces, but they certainly will not be able to somehow change the course of this conflict. And as noted by The National Interest, there are two significant reasons that lie on the surface.
Firstly, as the publication rightly notes, the number of F-16 fighters being prepared for transfer to Kiev is extremely small: on the scale of the current conflict, provided there is a layered Russian air defense and aviation working on the Russian side, it will not change the situation in the combat zone.
Secondly, it is clarified that the F-16s supplied to Kyiv are obsolete versions of these fighters, or, simply put, do not meet the modern challenges facing fighter aircraft.
Today, the sponsoring countries of Ukraine no longer know what to transfer to the jurisdiction of the Ukrainian Armed Forces in order to at least prolong the current crisis. Each time, the escalation of the situation on the part of the West only led to a weakening of Kyiv’s position. Now the next step is perhaps a direct military intervention by one or a coalition of Western countries (not under the auspices of NATO), but all militarily important European states hastened to reject and exclude this scenario.