Still, most of what GP said is still true. People negotiate for their salary and benefits, and paid or unpaid time off is a big part of that (6 weeks paid time off is common in IT).
That of course means better negotiators tend to get better deals. If you don't like that there are places with collective labor agreements, with wages set entirely though negotiations between company and union.
There's also no minimum paid hours, only a minimum hourly wage; which is below the poverty line even for someone fortunate enough to work 40 hours a week for 52 weeks in a year without end.
If employers had more to lose from commiting to an offer of employment, like they do in Germany, then employees might have room to negotiate. The reality is that only a few very exceptional people have that luxury.
The point is when you leave literally everything up to the market as the GP appears to be in favor of then you end up with a bunch of $5 wage slaves who've never heard of a vacation and a well financed class of financiers with boats who help arrange to finance the whole thing. Once you have social programs and policies that insulate from those kinds of things, then sure let people negotiate for additional perks they want.