I too only have anecdotes from myself and friends/colleagues, but a few experiences stand out:
* The accountability culture really matters. Are teams responsible for their own commitments/deadlines? If you think you might get fired, or at least a lower performance review for taking vacation (because you shipped less while out) then you are less likely to take vacation. Of course the problem here isn't the PTO policy, but unlimited PTO in a company like this is worse than a defined amount of time.
* Are senior leaders work-a-holics? If so, that might breed a culture where, even these same leaders always say the right things about everyone needing to recharge and take advantage, the ambitions see those above them, and ape the behavior of working more. This trickles down, though it might be inconsistent across the company.
* As time has gone on with these being more common, some strategies have emerged to take advantage of them more effectively. Such as being more aggressive with 3 day weekends, or flex schedules, or remote work, or vacation hybrids (like going abroad for a 6 weeks and working every other week). Taking a bunch of multi-week vacations may or may not work in your company, but figuring out the broader category of "flex work" seems to be getting a ton of experiment.
And whether or not you do take it, you can if you need/desire to do so.
It stands in contrast to more traditional companies that offer you two weeks to start and an extra week after three years of service without a raise.