Twitter thread on why the Russian army is so weak, and so poorly led:
View: https://twitter.com/kamilkazani/status/1502673952572854278
Tl;dr - Soviet leaders of times gone by, as well as Putin in modern times, fear a strong and capable army as it has the power to overthrow them. Therefore after they have fought wars, they eliminate the popular and efficient generals that might be a problem, leaving the worst ones in place, and make up the difference with officers from the loyal State Security forces who have no military experience. They also ensure that the army are the lowest on the totem pole, below state sponsored mafia types.