A single mass riot event would not overthrow a government with the second most powerful military in the world, particularly not one that historically doesn’t give a fuck about openly murdering dissidents.

Instigating real violence against the government would turn public opinion against the movement and would turn them into terrorists rather than human rights activists. Better to maintain the moral high-ground, gain widespread support, and then burn the house down when the moderates finally open their eyes.

If everyone in the nation sees the government brutally slaughtering peaceful protestors, they will begin to understand the true nature of their subjugation. In contrast, if people who burned down cities and murdered officials are executed, the average person wouldn’t care because bad things are only happening to “bad” people. The key variable is not the extreme ends of the spectrum, but all the people in between. If the rebels can’t bring most of them over to their side, any revolution would be stomped out in days.