My guess is that Russia is trying to create a threat to NATO countries so that those countries will want to hold onto their defense materials and weapons instead of those going to Ukraine.

NATO is not exactly strapped for materiel at the moment, especially if considering quality vs. quantity. Given the way that an Israeli F35 was able to operate with impunity a short while ago, I don’t think the old Soviet gear would fare too well. https://theaviationgeekclub.com/iriaf-commander-reportedly-fired-after-he-kept-secret-that-israeli-f-35-stealth-fighters-had-violated-iran-airspace/