I imagine it's really hard for employers to balance that, though.
A good employer wants employees to take the time off they need without worrying about running out of PTO to do the stuff they want. They don't want an employee to ever have to think "Shit, if I take that day off for a dentist appointment, then I won't have enough PTO for that weeklong trip to Hawaii!"
But if you try to avoid this scenario by being extremely generous and declare an explicit 8-week PTO policy, then you will have people using 6-8 weeks PTO. Even as someone that strongly values work-life balance and PTO, 8 weeks is pretty nuts. If everyone took 8 weeks PTO every year, that would be pretty costly and could significantly impact productivity. 8 weeks is 1/6th of the year! It would cause chaos with people frequently coming in and out of the office.
So I think an unlimited policy sounds good, but expectations have to be set. Personally, I'd like to see it paired with a 10-day MINIMUM policy, with at least one full week off.