One Ka-52 helicopter deflected 18 MANPADS

"The Vitebsk-25-mounted helicopter was then fired upon by two dozen Russian Igla MANPADS missiles, none of which hit the target."

I suspect few of the Russian equivalents of the F-16 have been taken out by AAM, and they're withheld because of the risk, yes. But to argue from that there is no sense in Ukraine deploying this class of Jet I think is a false equivalence. It depends on the relative strengths and weaknesses of AAM, and radar systems. If enough of the Russian tactical field deployed radar are out of action and if they can't fly AWACS then, it might not be symmetric.

Basically "porque no los dos" -fly UAVs and fly jets, and find out what works.

I think its likely that logistics is winning this war. The evidence of a lack of depth in parts and maintenance in the background inside the Russian forces is marked. In order to field their top-line jets here, they have to be willing to lose them and the evidence is strong they aren't willing to risk them. If the Ukranians are donated F-16s, perhaps their willingness to lose them will be higher?

I hate the WW2 battle of Britain comparison, but it stands out: every german aircraft lost over the UK was a lost crew as well as an aircraft. Switching from attacking radar and air fields to mass bombing was a massive tactical mistake for the german forces. They wound up unable to sustain the losses. The British were willing to tolerate the attrition in bomber crews later on in the war, to horrific effect.

In that sense, losing Russian pilots and aircraft against weak logistics and pilot training, disadvantages the Russians more than I believe the Ukranians will be disadvantaged by deploying the F-16s at some risk of losses.

Russian air losses in WW2 were catastrophic at times, mainly because of asymmetric capability in the aircraft and weapons. They lost an entire cohort of crew.

Obviously if they deploy in an offensive role without standoff weaponry, the risks tend to equalise.