Why should an equilibrium price be allowed to stay?

You are talking code words. "Equilibrium price" is not a carefully defined term. It means whatever you say it means. "Allowed" prompts the question "Who does the allowing?"

In a free market the price is set by agreement between seller and buyer. Every price is an equilibrium price, and "allowed" means nothing. So you must be talking about an unfree market, and that always means everything is determined by political influence and enforced by cops, in which case "equilibrium price" means nothing.

You need to examine your assumptions and consider what the words mean. Everybody uses code words and assumes that you know what they mean. But you don't always think those words mean the same things that others think they mean. Life gets very complicated that way.