Everyone gets according to their contribution. That’s something communism and capitalism actually have in common. However capitalism takes into account uniqueness, results, and innovation. In communism you get rewarded just for doing something. No matter how shitty the thing is, no matter how lazy you are.
In capitalism you get according to how critical and innovative your thing is. So yeah, most people aren’t very critical or innovative. So why would they get much?
Oh, you can scan groceries or flip burgers — you should be able to buy an apartment in a large urban city. Doesn’t that strike you as a bit silly?
Also, we need wealth gaps so that people would be motivated to invest and grind and strive.