“We” do, we could, if organized. Per your first point, that is the problem today - agreeing on a shared goal rather than infighting about all the peripheral issues.
I would hazard a guess theres stuff that I don't agree with you on, and we would want certain laws written differently. Its important to remember that we all vote for what we think is right, based on a system evolved over thousands of years to cater for human fallibility. The modern rhetoric of "us against the billionaires" is simply not how the world works, despite how much people want it to.
The comment was about 'us vs the ruling class', which is very much how the world works.
Your knowledge of history is equally flawed, if you believe modern democracy is some kind of evolutionary apex tenderly nurtured for the greater good for thousands of years.
Thats only how the world works when you want to paint yourself as a victim. Lots of people have gone on from nothing to build something of themselves in this world and become peart of the 'ruling class' because you know, thats the capitalist society we built with opportunity for all. You can either take opportunity and grab it and build something for yourself or sit and complain the billionaires are holding you down. I know which one I am doing.