Better for everyone because the talented H1B employee is no longer shackled to their employer and can leave demanding a higher wage and raising wages for everyone.
Well you just answered why they don't/won't do this.
The H1B employees being shackled and thus having little to no leverage to demand higher compensation or better working conditions is (from the point of view of the companies abusing the system) a feature of the system, not a bug.
I guess you’re proposing eliminating the h1b program to raise wages. That would maybe work but our companies would theoretically be less competitive globally. If we’re going to allow immigration based on professional skills then these people should be fast tracked to having the same employment rights as natives otherwise it creates a subclass of workers that depress wages because those that belong to that group will be too risk adverse to ask for more money knowing that they’ll likely have to leave the country if they get let go.