In a world where employees and employers have equal bargaining power and knowledge what you're saying makes sense. Given the opportunity though, businesses will do their best to hire workers that they can pay as little as possible and work as much as possible. It's the natural state of profitability to tend towards such a situation. In general this means there's a tendency towards increased work for lesser or equal pay, fewer benefits, poorer working conditions, etc. etc. Without a force pushing back on businesses in the form of regulations they will continue the race to the bottom as that is the most profitable thing to do.