Put these together, and at the end of the day, the vast majority of political activity is empty gestures that sum up to <Yay us! Boo them!>
Second: everyone wants to look good, and it's easier to talk the talk than to walk the walk.
So you get meme sharing, slogans, and slacktivism rather than real policy proposals. You get guaranteed to fail bills in The House to make Reps look like they're fighting.
People don't support/oppose a $15 minimum wage because of economic reasons. They do so for tribal reasons.
People don't support/oppose gun control because of safety reasons. They do so for tribal reasons.
And so on, down the line.
First: people are very tribal. Even in America, where most people don't know their ancestry, or it's very mixed, people line up with their political allies in a tribelike fashion.
And this means that most of their positions are based on their tribal affiliation.