There is one way how capitalism can work, and it did work for a while:

Worker action, from voting to unionisation, strikes up to revolution are all things that happen under the umbrella of capitalism, and as much as capitalists want to ban that, it's all just part of the same coin.

If capitalists play nice and fair, pay good wages and make sure the workers have a decent live, then the system is stable and as a reward they get stability to make business.

If they get too greedy and squeeze the workers too hard, workers push back. They form unions, vote left, start striking, and in the worst case they destroy equipment and start a revolution. This is the kind of power that the people have.

In theory.

Due to clever manipulaton, the capitalists managed to divide the working class and pit them against each other. This worked fine for a few decades, but it's wearing thin. It will take maybe 5-15 years until it all comes to a head and explodes.

And OP is right. Back in the day you had to get the military to shoot their own people. With automated weapon systems and AI/robots performing more and more of the productivity, this balance shifts rapidly, and it will likely lead to a total system breakdown with unforeseeable results.