Sanctions have not succeeded in lessening support or creating regime change. They are a siege warfare tactic, and a way of inflicting suffering upon the masses of people. There’s plenty of books on the topic, I’d recommend Sanctions as War, edited by Stuart Davis and Immanuel Ness.
Are people in Ukrainian controlled territories free to protest against forced conscription and withdrawal of passports? No, they will get put into prison, and given a choice to join the military or serve a long sentence.