someone needs to do work to get anything

The issue isn’t that someone needs to do work, it’s that some people are forced to do more than their share of work so that other people can do less. There’s a class of people who get money without having to lift a finger just for owning stuff (land, residential buildings, companies, etc.). When there are people who get money without having to earn it through work, that means there must be other people elsewhere in the system who are paid less than their work is worth. And there’s not a damn thing they can do about it, because the owner class can simply refuse to pay them more, so the workers’ choice is between being exploited or starving. The workers can’t just go and find some land to claim as their own, it’s all owned already.