They are not useless in the sense that they are visible and at some point the state cannot only respond with more violence from police force forever or else the dictatorship becomes assumed.

But current protests aren't revolts nor violence anyway. There is side/peripheral violence but that is not the point of the protests

   the state cannot only respond with more violence from police force forever

As long as they control the media narrative it's all good it can continue for a long time

Revolts don’t need guns. Look at Nepal. Look at Bangladesh. Look at the Arab spring.

When people are so pissed off that millions of people take to the streets governments fall.