I've also heard that Ukraine has been cutting deals with arms manufacturers to allow them to test their new gear in real battlefield conditions. Russia is not enjoying that deal.

America lost 58,000 in 10-15 years of Vietnam, and 4000 in 20 years in Afghanistan. Putin has lost over 1.3 MILLION in only 4 years! It's a meat grinder.

They went from volunteers, to a draft, to prisoners, to snatching military age males off the street, to mercenaries. They are running out of options for warriors. You can only kill so many children before enough citizen parents get pissed off enough to make things really hot.