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.…
Whoever is responsible/culpable doesn't matter. Sanctions aren't about punishing the population, they're about inciting a change. A happy population doesn't riot and revolt. You need a miserable population to get something like that to happen.
Throughout history, revolutions only succeeded when there were enough privileged people on "their" side (eg. those with money, status...). I am not sure where the idea that sanctions work to this effect came from, but I have yet to see it: miserable population is scrambling to survive, not to fight ideological battles.
As an example, Serbia, where I am from, has been under heavy sanctions in early 90s: you'd be buying car fuel in 1.5l bottles smuggled from neighbouring countries, inflation was so bad that the day after paycheck, I'd be getting half of my parents salary for pocket money... Economy started recovering in late 90s after sanctions were abolished, and regime change happened in year 2000.