Every protest is a sea of organization. Thousands and thousands of people convening in a public space for a cause compels people to think about those next steps. It's a process of breaking inertia. But yes, these always require a politival mechanism: support for a bill, a race, a party, etc or they will get co-opted by the ruling class.

That's what happened with Occupy Wall Street, yes, though it still resulted in a major wave of political organization. The movement being ignored resulted in a major wave of disenfranchised people who turned to fascism thinking it would be a viable alternative. But at the same time it helped prime people to actually give Bernie a chance in 2016.