This is an overly simplistic analysis of the situation.If enough people in Russia were against the war and against their dictator, they’d Get rid of him
Russia is a repressive regime. Human life and rights mean nothing to them. It means nothing to the regime to pile people into gulags and camps in order to suppress dissent. This has been the way in Russia for centuries. More opposition? Meh. Open more camps in the East.
Too many war dead coming back from Ukraine? They have an easy fix for that, too. Mobile crematoriums. So when 1 year conscripts are sent into a battle that's supposed to be an exercise and are killed in combat, they just cremate the remains, send them home in a cardboard box and tell their mothers they died in a "training accident".
The person, as an individual, and as a life has so much less value in Russia it is hard for outsiders who have not acquainted themselves with the history and culture of this part of the world to comprehend it.
The people in Russia can no sooner get rid of their dictator than people Venezuela or North Korea can.