Until the moment companies once again collude to drive and hold prices down. Suddenly those competitors aren't too low after all and the "tried and true" isn't so useful.

Corporations have enough staff that they can lay off hundreds or thousands of workers without a single worry. They can hold out not paying you the rate you want for much longer than you can afford not paying your bills and eating. Eventually, you will accept a lower salary and if you don't there are plenty of others who will. The vast majority of all employed people have next to no leverage compared to the companies that hire them and companies know it.