Here my two cents as someone that has visited, lived in, or good friends in authoritarian regimes such as East Germany, Russia, North Korea, Iran, Hong Kong: - in a democracy, the population is responsible for what the government does. Conversely, the more authoritarian the regime, arguably the less culpable the population is. (Of course, people shouldn't have allowed an authoritarian figure to gain power... indeed.…
You highlight the difference well between a democracy and an authoritarian regime. However the suggestion you make at the end, that we should only sanction Putin & co., is exactly the type of measure that would work in a democratic regime but not in an authoritarian one. I can't think of a single case where a large authoritarian regime was handed off gently to a democratic one as a result of sanctions on the dictator…
I live in Serbia which was under heavy sanctions in early 90s: those in power have only gotten richer and more powerful during the time. Only after economy started recovering in late 90s, and people could afford to worry about "freedom" instead of basic survival did people get enough democratic momentum to vote incumbents out (sprinkled with a bit of West-supported protests to avoid a possibly rigged second round with 47% votes for opposition to 32% for incumbents in the first round iirc).
But sanctions did nothing to hurt those in power. They did plenty to hurt the rest of us.