This paragraph is of great interest:

Russian tank losses have been enormous in this war, amounting to the equivalent of around 16 tank regiments worth, which is likely hindering Russia’s ability to reconstitute its tank units rapidly. Recent intelligence estimates presented by Dutch open-source investigative organization Oryx and the British research institute International Institute for Strategic Studies (IISS) depict these losses clearly. Oryx verified over 1,000 distinct Russian tank losses and 500 captured tanks on February 9, which likely means that Russia has lost half of its pre-war tank fleet in the first year of the war.[13] IISS similarly noted on February 15 that Russia has lost about 50 percent of its pre-war number of T-72B and T-72B3M main battle tanks.[14] A single tank regiment requires just short of 100 tanks, so rebuilding two tank regiments from scratch (as the 12th and 13thTank Regiments likely required) would demand 200 tanks, which the Russian armed forces do not appear to have in usable stocks and do not appear able to produce quickly.[15] Widespread tank losses also impact the capacities of motorized rifle formations to function effectively, but motorized rifle units require fewer tanks in each and can make better use of the large amount of relatively untrained manpower the rushed Russian reserve mobilization has generated. The absence of reconstituted tank regiments and brigades, however, deprives the Russian ground forces of the kind of punch required to make and exploit operationally significant breakthroughs.

Source:https://understandingwar.org/backgrounder/russian-offensive-campaign-assessment-february-19-2023