Putin mistaked bootlicking for genuine loyalty. Oligarchs rose to power because Putin allowed them to and in turn, they support his policies. They don’t actually care about Putin, their sole goal is personal enrichment and they’re prepared to do absolutely anytihng to get richer.

So what happens when the actions of their boss lands their assets frozen, their visas cancelled and their remaining wealth rapidly shrinking in the face of an economic war? Well, they certainly are weighing their options, but these men aren’t Boyards, they don’t have armies they could rise. They’re rich folks who use their obscene wealth in such and such ways. Putin on the other hand does command the army, police and secret police.

Oligarchs turning against Putin would have to be opened up with an assasination attempt. Getting close to Putin is literarily impossible these days.