You mean like how I freely negotiate and accept the contract that describes CPUs backdoors (Intel Management Engine) in one of two computer CPU manufacturers in the world?

Or your cellphone contract, or apartment lease, or the terms of use for every web site, or End User License Agreements. They're all totally "meeting of the minds" mutually agreed upon between parties of equal power, open to negotiation by skilled end-users... LOL! Most contracts/agreements that end users are subjected to are far from freely negotiable. They are take-it-or-leave-it rule-making written by some company's legal counsel and enforced by the courts. Agree or don't do business with.

I've never been presented with an employment agreement where any of the terms could be negotiated. Salary and benefits? Yes, sometimes. But other terms? No way. I always try, but in every case, you get a stern message from corporate legal basically saying "Sign it unmodified or GTFO." I don't know who these HN Captains of Industry are who negotiate the terms of their employment, but that's the exception, not the rule. Maybe at the VP+ level, these things are negotiable (parties are more equal in power), but at the "5th grunt from the left" level, no way.

This is the point of unions, because atomized workers don't have much leverage by themselves to negotiate with an entities that have already consolidated their interests and power in the form of corporations. Unions help workers consolidate their interests and power in order to leverage them against the consolidated interests and power of their employers and negotiate better terms of employment.

Negotiations exist between a single employee and an international team of Amazon lawyers and professional negotiators. Whether that should really count as "two parties" negotiating on equal terms is up for argument.