I love this idea: zero profit capitalism. Sure some people would abuse savings accounts more than others, but taxing standing profits on a gradually increasing scale the longer they stand (sure the market already does this at a minute level, but it's not enough to deter wealth hoarding) seems like an effective way to solve the wealth extraction problem corporations introduce.
Sure you won't necessarily meet demand, but there's no inherent reason quality need suffer(?).
Or, have a coop where staff wages soak up all excess revenue, giving zero profit.
You'd want a contingency, and a savings account if you seek to expand the business, but they're not profit.
We could do that with all businesses I think.