So why is Russia losing so many tanks, so many crewmen?
The answer can be found in two things: Russia’s ongoing demographic collapse and the Russian military’s sad lack of training.
https://pjmedia.com/vodkapundit/2022/04/13/ukraine-war-have-missiles-made-tanks-obsolete-n1589423
...consider the last time Russia suffered such a humiliating naval defeat, in the 1904-1905 Russo-Japanese war, that defeat precipitated massive loss of prestige, unrest, military revolt, and revolution in 1905 and was a major nail in the coffin of Tsarist Russia...
https://smallwarsjournal.com/index.php/jrnl/art/why-russias-navy-ukraine-war-doomed-or-irrelevant