The Ukrainian air defense was not even close to modern. It consisted largely of older S-300s, some Tor, Buk and Tunguska systems that were leftovers from the fall of the USSR. They had some even older systems (S-75, S-125, S-200). So this is largely 30+ years old, and not very well maintained.

Apparently the S-300s were maintained enough to spook the Russian AF. Also, there’s a variety of Western systems now.

I wouldn't be surprised if they've completely depleted their inventory of S-300 missiles (5V55KD). The Texeira leaks seemed to indicate they would run out by Summer/Fall of 2023, though with the supply of IRIS/Patriot/NASAMs etc, they might have reserved some of them.

S-300 is not really comparable in terms of capability to S-75 and S-125. There is a quantum leap between decentralized networked mobile IADS with a combination of radar types and missile types and Iraq's S-125 systems.

S-300 is still a very capable system today and 1990s' S-300 systems are only really a generation behind modern systems. They're about as recent as the systems on Ticonderogas and Arleigh Burkes that are very much still in service today.

Yeah, I wasn't really trying to compare S-300 to the older systems. Just that they were some of the systems Ukraine had or have brought back into service after the invasion.

S-300 (and S-400 which is really enhanced S-300) in their most modern configurations are incredibly lethal systems against 4th Gen aircraft that aren't accompanied by extensive SEAD/DEAD resources and jamming. But Ukraine has 1st generation S-300P, from the 80s. These might have been upgraded to S-300PT-1, giving them cold launch with the newer 5V55KD missiles.

Can’t believe the Ukrainian AF is still flying after 2 years - Wow

6 hours from Russia and they still can’t take them out

I think you might be conflating airforce with air defense. There’s not a lot of Ukrainian AF flights these days and when there is, it’s more often than not, one way (unfortunately) with loaned gear. It’s why they’re asking for F-16s and more AD.

It's hard to say that without having inside information. That Ukraine has managed to keep any of their aircraft flying in the face of far superior numbers is astounding. They are still managing to launch SCALP from SU-24m frequently (as frequently as the limited supply of these missiles allow). Considering they're probably outnumbered 5 to 1, that's either indicative of operational excellence on their part, or Russian inadequacy.