Labor is a commodity and it obeys market forces (given adequate information); employees get paid salaries because they are selling their time. Employees are replaceable - when one leaves, they are replaced by an equivalent, and the show goes on.

I think the current (labor) sellers-market that's happening in tech sector gives the illusion that this is not the case, and that we are auctioning high-value, rare skills and not sellers of commodified labor, which has congealed around standardized tech stacks that make sure you're the right type of cog.