Law Firms are one example where it could work, but even there you have Partners and Associates. And even Partners have levels (Equity Partners, Junior Partners, Full Partners... etc).
Communism itself has many flavors, and while soviet communism failed (arguably because it was just tsarism with a different tsar), Chinese communism is still very much a working model and a very successful one (for some definitions of success.)
Democratic socialism is also well represented today, with some stand-out performers in Europe.
As with all social systems, capitalism included, there are pros and cons, haves and have-nots. Some systems promote equality, some promote huge winners and losers. Naturally US businesses tend to model the national system (the only thing that matters is money) which typically makes them poor places to work.
But companies don't have to follow the national model - there are plenty of exploitive companies in Europe, and more than a few humane companies in the US.
During the Cultural Revolution, China tried to become "more communist" economically, with predictably bad outcomes.
Your 80/20 speaks to remuneration, which can be negotiated and does not have to be equal, especially when equality isn't fair.