That's something you'd expect Snidely Whiplash the Evil Capitalist to tell labor to make them feel bad about negotiating with him, but I don't think it actually works that way. Costs are costs and money is fungible; a dollar extra negotiated doesn't come out of the pockets of another employee any more than a dollar spent on SaaS comes out of the pocket of an employee. Corporations might create internal fictions like e.g. headcount budgets to make this less obvious, but a) fiction and b) Snidely Whiplash.

Here's the acid test: who gets a bonus if your company happens to hire five doormats in a row? Is it the best negotiator on the engineering team?