If the second most powerful army in the world is pulling T-62 and T-64 tanks out of storage, refurbishing them, and deploying them in a combat operation, it is self-evidently running out of steam.
This would be like the United States pulling M60 tanks out of junkyards and off VFW hall pedestals and sending them to Iraq because "things are going so well".
The second best army in the world is also buying artillery shells from North Korea and begging countries they recently sold modern military hardware to to send them back.
If I were a super power involved in the Ukraine war, I'd keep my best troops and equipment back and push old junk to the front to hold the line. When I managed to get a break through, then I'd push the new stuff through the breech.
Exactly. If you have old ass tanks that are easily refurbished and work perfectly fine for current needs and will likely never have a chance to use again, why not. The US uses old shit all the time. The KC-135 Stratotanker is still being used and is over 70 years old at this point