Ive seen it argued that one reason some of the more notorious incompetent people high in Russia’s leadership havent been replaced, is that, if youre an autocrat like Putin, you dont necessarily even want competent people running things like your military. You dont want them so incompetent as to endanger your military’s ability to function obviously, but someone who knows what they are doing is potentially a threat if they decide to launch a coup and are equally competent in pulling it off, and known incompetents can be a scapegoat to blame when things go wrong.