The success of diplomacy and peaceful protest hinges on the existence of a credible threat that the alternative (war and riots, respectively) will be worse. Even if a (mostly) peaceful solution should be found, I suspect there will have to be some measure of violence to get that point across.

As others point out, the elites won’t go down quietly, and as long as there are bootlicks willing to fight on their behalf, they’ll rather let their bootlicks die than make concessions.

So while I don’t think violent revolutions are good for their own sake, they may be a necessary evil for good ends.