There are some interesting wars around, but non is a good measure regarding air defense and air force. The last, which we could look on are wars in Ukraine, in Syria and Iraq and in Yemen. In all those wars air force is only on one side and air defense on the other side is the same in all of them and is composed with AA guns and MANPADs. Novorussian army capture 10 Osa-AKMs in Debaltsevo so in the time of high war, they were not available for them.
When we look at Ukrainian air force, it is very large on paper, but very few flying. Good indicator was in Crimea, where Russian army capture 45 Ukrainian MiG-29 fighters, but only few was in flying condition. 37 of them Russia return to Ukraine. After the fall of USSR Ukraine sell a lot of their planes around the World as well as spare parts for them. Consideing, that Ukrainian army is also low on money, there is a good question, how many of their planes Ukrainian army is able to repair and bring in flying and combat condition. Other thing is, that Ukrainian air force doesn't have PGMs, so they have to attack with dumb bombs and rocket launchers. Ukrainian planes are not modernized like Russian Su-25SM and Su-24M2, which are able to attack targets from high altitude to avoid AA guns and MANPADs. Ukrainian MiG-29 and Su-27 fighters are air defense fighters only and are not multirole like Russian MiG-29SMT or Su-27SM with multirole radar with ground attack modes and with newer IRST, which also have TV channel and laser designator, that it could be used against ground targets as well. Only capable jet is Su-24M, but they don't have PGMs for them and there is also a good question, how well they are maintained. Next problem for Ukrainian air force was small number of flying hours for their pilots and question of quality of their trainings. All this bring Ukrainian planes to fly quite close to their targets to attack them and with that they expose themselves to Novorussian air defense, which impose to them quite heavy losses and we as well don't know, how many other jets and helicopters were hit and damaged and if Ukraine is able to repair them. Ukraine doesn't receive spare parts from Russia and eastern European NATO members didn't have Su-24 and Su-27 in their armament, so they could not supply Ukraine with spare parts either. So Novorussian air defense with quite small strength was able to secure their air space from Ukrainian air force, which is more result of 25 years of "investments" in their air force than in strength of Novorussian air defense, which is actually quite weak. Ukrainian war could not be a model of air defense effectiveness, than a model, what happened, if you didn't invest in your military for a longer period.
Second war is in Syria. Syrian air force have only a few MiG-29 modernized to MiG-29SM level and around 20 Su-24, which are able to strike targets from high altitude to be safe from terrorist air defense, which also have modern MANPADs, large number of AA guns and even some Osa and Kub SAMs, if they are not already destroyed. The rest of the planes are old MiG-21, MiG-23 and Su-22, which have to fly near target to hit it, so losses between them are quite large. As I know Syria loss few Su-24, which were shot down by Israel over Golan and no MiG-29 was lost for now. That there we got a contingent from Russia, which was by numbers still smaller than Ukrainian air force and engage far larger enemy than what Novorussian army is today. In half a year they bring excellent results, unfortunately Syrian army on the ground was too overloaded and weak that they could make more gains on the ground. Air force could not win the war, but could bring a lot of support to the troops on the ground.
Third war is Yemen, where Saudi coalition have excessive superiority in the ground and in the air. They have a large number of modern F-15S, Tornado, Eurofighter, F-16 and Mirage-2000 jets as well as Apache helicopters and other side is also depending mostly on MANPADs and AA guns. True, Saudi coalition suffer some losses to crashes, but some Apaches were shot down by guns and Emirati Mirage-2000-9D was shot down by old Strela-2 (SA-7) MANPAD. And all this air superiority of Saudi coalition didn't bring any success to their ground troops in ground battles, where they lost battles regularly. Saudi coalition mostly control desert part of Yemen, while Yemeni army and Houtis control more populated highlands and even part of Saudi Arabia. What lessons could we take from Yemen? Only one, that incompetence and cowardice are decisive factors in a war and that even numerical and technological superiority could not save you from defeat.