It won’t always be the same ones so I’m unsure of what you’re asking. Which ones invaded the spaces I listed before?
For Revolutionary Catalonia it was the Nationalist Faction who overthrew them. They advocated for, and implemented, a form of national syndicalism that was “fully compatible with capitalism”.
For Red Vienna is was the fascists who overturned the socialist policies and returned the city to a state of capitalism, allowing land-leeches and other bourgeoise to return to continue exploiting the working class.
Building off this, people have to look at more than just the protests. “Radicals” shape the Overton Window, think Malcom X.
In a world where nobody protests and nobody is participating in radical activism, nothing changes. In a world where there are protests but still no radical activism, there is usually no change, though the media and capitalists will feign care and “listen to the issues”. When the protesters become the moderates, the ruling class finally cedes some power to stop social revolution.
In a world where there are only radical activists, no moderate protesters or passive bystanders, there would be social revolution, monumental change. This has happened before, and it’s why the ruling class concedes changes as the overton window becomes more radical.
To a lot of people this looks like “protests work!” but it’s not the protests primarily, it’s the threat of social revolution, led by the radicals and supported by the new moderate position of protesting against the status quo.