A lot of what you say is not false, and it can be frustrating for employees (though it goes both ways - imagine a company headquartered in, say, Chicago, and you lived in SF or NYC - you'd be better off than if you were getting Chicago market-rate)

Hiring full-time remotes in a major way is still a relatively new practice, so we'll see how it all shakes out. It may very well be that actual pay-by-value takes root, but I wouldn't hold my breath. Pricing and markets are curious things, and there is huge inertia.