The company doesn't want to give anyone a raise. They are not happy to give anyone a raise. Companies do not willingly increase their costs, full stop.
You could maybe make an argument that companies may increase wages for high performers for retention reasons, because needing to replace valuable employees is a large, if somewhat intangible cost, but that's pretty iffy. Companies are made up of and managed by humans, who are notoriously short-sighted and willing to discount potential risks when there are financial incentives to do so.
50% of the time Joe Useless makes more than you do already, because they joined later and market rate for the position shifted upward. You'll still need to fight tooth and nail, alone, individually, to reach parity, even if you're a top performer. Your manager isn't usually going to say "hmm, we're paying Joe Useless 1.2X, while we're paying Sally Superlative 1.0X--we really should pay Sally 2.0X! Your manager will be overruled by the CFO if they do suggest this anyway. Large wage increases based on expertise happen because you're able to better sell yourself to _another_ company when changing jobs.
Ultimately, I'd prefer a system where Joe Useless and I fight for equal wage increases collectively, because the balance of power is such that we're more likely to get them than each of us going it alone. Joe Useless is gonna be there anyway unless the company decides they're so useless as to fire them. So long as Joe Useless is there in the same role as I am, I don't care if they get equal pay, especially not if they're helping in the fight for increases in our equal pay.