It wouldn’t make much sense for Russia to show their cards and use modern war tech on Ukraine, a country with a (relatively) primitive military. They’re barely even using fighter jets.
Occam’s razor is more likely - the west vastly overestimated their capability practically the entirety of the Cold War, and you’re doing it again now.
Maybe because they've barely been training those pilots and know the planes would likely be lost if used above Ukraine? Pilots in the Russian Air Force have supposedly been averaging less than 100 flight hours a year, which is next to nothing.
Tanks being used by Russia in Ukraine:
T-72A T-72B3 OBR.2016 T-80BV T-80U T-80BVM T-90A
IFVs:
BMP2 BMP3 BMD4M
SAMs:
Tor Buk Pantsir
Fighters and Helos:
SU-25 SU-30/35 Su-34
Mi-24/35 KA-52 Mi-28
None of this is "monkey model" stuff like the the USSR sent to client states. These are all top of the line. Same with the artillery and missiles used. All the best the Russians have in any decent numbers.
https://www.google.com/amp/s/www.nytimes.com/2022/03/14/us/r...