It's not socialist but it basically portrays the rich of the capitalist system as outright actively evil by simply existing as they do.
Famine, Affluence, and Morality by Peter Singer
https://rintintin.colorado.edu/~vancecd/phil308/Singer2.pdf
Should be required reading but it will never be under capitalism. Basic rundown:
Most of us view an act as immoral if you can only be trivially inconvenienced to literally save a life. Like, If you saw a toddler drowning in a shallow pond that you could reach out and grab the poor child but chose to ignore it obviously and walked on letting the kid die then we'd almost all universally declare that an evil act. What if you had to get your shoes wet? What if you didn't even need to do that, you were across the street in a second story apartment but you saw the child and another person was walking by? Would it be immoral not to alert that other person with a yell to let them know they could save the child? We would all agree, you still have the responsibility morally. To not do so is immoral. Well, what if the dying child were across the world and there were already people there wanting to help. All they needed was a few dollars. And what if giving that few dollars was easy. Digital payment. Scan a code. Isn't it just as immoral as not reaching down to lift up the toddler? Just as immoral as not yelling to the person to alert them? Even more so because you know for a fact that the person will help. This is what Singer argues. And he argues that the more able you are financially to help the more immoral your inaction is by not doing so.
Anyways, if you try and debate my clumsy summary you are a lib and will be ignored when the actual paper is linked and pretty short and extremely easy to read. This paper is controversial only because it paints most of the successful people in the global north as properly evil by there mere inaction.