Whoa, what a groundbreaking idea this is.
I don't think anyone is advocating for the end of capitalism. At least not any relevant group. What people are actually advocating for is a more equal capitalism. A capitalism where the top 1% doesn't hold 50% of the wealth. A capitalism where people don't die because they made the mistake of getting sick and not being able to pay for the cure. A capitalism where everyone can get well-educated and a capitalism where we don't destroy the planet we live in. A capitalism where you don't get punished for being something you didn't choose to be.
The phrase "capitalism made our lives better" is also only true for portion of the population. I bet the people who have to skip meals because they don't have money to buy them don't agree with that. Neither do the people who were forced into dictatorships because another country wanted cheap oil.
I mean, it's great that the middle class in the United States has access to healthcare, education and comfort. What these people you criticize are trying to do is granting that for every human being.