Feudalism was resisted by peasants from the start, but successful anti-feudalism was limited prior to the 1500's, and demographic and the literal climate shifted to fuel subsequent revolution. But even then, these revolutions were only apparently revolutions after they were won.

The Civil Wars that rocked England were not obviously class based revolutions at the time. Even the earlier merchant republics were not seen as an existential threat to the feudal order.
Only the French Revolution truly woke the world up to the new order.

The fall of capitalism might follow a similar dynamic where it's weakest link are picked off by outright revolution, and it's strongholds shift toward socialism through proxy struggles/need to survive.

Climate change might provoke capitalist powers such as the US to bring itself closer to socialism as a survival tactic. More centrally planned economies and nationalization etc etc, and then that will set the stage for a less dramatic break toward outright socialism.