The answer is you already have the 40k person, it’s not broken, there’s no urgency for HR to approve additional funding.
That person says they’re leaving, now HR can approve a counter offer, but also, can you trust they won’t leave later? Maybe we shouldn’t.
You’ve failed to give a raise and they’ve now left. Now there’s a gap and the team can’t pick up the slack. Oh shit, guess we better hire someone else. Oh, the market average rate we all pay the same company to provide says the rate is higher than 4 years ago, so they get hired with the higher rate.
Isn’t that unfair to the existing employees? We’ll see point 1. It ain’t broke, we can’t approve more funding.
This is why the idea of maintenance is something that should be better appreciated. If that person’s pay kept up in the first place, an employee can expect to not need to find another job and the problem never appears in the first place.