The fact that this is not happening at a grassroots level in the US would suggest that it's not as big a deal to Americans as the Europeans in this thread think it should be.

Speaking only for myself, I've found that when I joined a company whose time-off policies I didn't like (only one so far), I just asked for more time off as part of the deal. The response I got was "sure. It's easier for us to give you more paid time off than more money."

On the other hand, when I joined a previous employer that (at the time--they improved) had fairly mediocre paid time off policies (not really that bad but it was the first time I had encountered PTO including both vacation and sick time and there was mandatory shutdown around the holidays). When I got what seemed like a pretty generous offer given I was making a relatively small salary at the time and the company was private so no stock, they also made it clear that the PTO was non-negotiable. Now, in practice, given my role no one was eyeing a few hours here and there to go to some appointment or a bit of personal time tacked on to business travel especially if I had traveled over a weekend, but the paper amount of PTO was just so-so.

> The way this worked in many places is that workers formed political parties.

Given the current political system(s) in the US, this is practically impossible at the federal level; difficult at the state level; somewhat more possible at the city level (eg New York City's Working Families Party). Third parties exist but generally have almost no influence.