If you’re in the majority, you have the votes to be able to accomplish something with reform. It’s not like we live in a monarchy, reform is possible under our system.
If reform isn’t working to bring about your goals, either your goals aren’t popular enough, or they are popular but the people lack the will and organization to vote for them.
If the people lack the will and organization to vote effectively, they certainly lack the will and organization to topple the government.
My area of expertise is managing complex systems and change implementation. I sincerely don’t understand how revolution is supposed to work where reform doesn’t. No one has been able to give me an answer that doesn’t bill down to idealistic hope. How is this revolution supposed to be implemented, and why can’t we build the foundation for revolution while simultaneously using the tools we have for reform? Wouldn’t widespread support for reform be the best possible proof of consensus?
Aside from what other people said here, all of which I agree with, you also need to acknowledge the super-structural grip maintained on the working class. People are hard wired to maintain the status quo, even against their own interests. The point of a vanguard party is that you are organizing the most politically developed people to set an example of revolutionary praxis which breaks people out of their stupor, ignites class consciousness, and empowers them to go against the status quo for the first time. Revolutionaries are a marginal group of people, the tip of the spear, which paves a new way in real time that your average alienated worker will see and follow because finally, something that speaks to their needs is being done and they now know what they can do to help. They know rallying around another bourgeois politician is a waste of time, but by definition a revolution is something new, actual change.
The issue in the US and Europe is that most workers are labor aristocracy and truly want to maintain the status quo because a more equitable world means their quality of life will actually worsen. This is why fascism is able to cannibalize these nations, destroying them in the process, and opening up space for the nations they imperialized to gain more power and usher in better conditions for the undeveloped nations.