The best solution is antitrust enforcement and removal of anti-competitive laws/rules lobbied for by incumbents. When companies have to compete with each other for labor and customers, wages go up and prices go down. Whey they consolidate they can charge monopoly rents.

Unions often even make this worse because they'll latch on to a monopolistic employer and then lobby with them to retain the monopoly at the expense of all the workers who are their customers rather than their employees.