It actually depends on whether the populace at large or the government in power are willing to maintain power through force.
If you’re dealing with a democracy and a populace like the US or the UK, there happens to be a limit of how much brutality they’re willing to stomach in defense of the system. In a lot of cases it’s much more than we’d like to admit.
If you’re dealing with an authoritarian government or a theocracy, that limit is much higher or non-existent.
What I am betting on is precisely that reluctance of the populace to stomach brutality. Whatever political victories are achieved through escalating violence are ultimately empty until a fundamental rejection of brutality is achieved.
So basically your takeaway from the fact that most of these successful social movements had a violent component to them is that social movements shouldn't be violent?
Most successful enterprises of any nature had elements of violence - "every fortune is built on a crime". I'm not questioning their success, just asking if we can do better.