This is why my previous employer moved to "unlimited" vacation.

They originally had a PTO-with-rollover plan until one day the CTO went to the president and said, "I have enough vacation days banked to take off October 1 to December 31."

They removed the rollover first, but then everyone wanted the last two weeks of the year off. There was never "a good time" to use one's PTO in other parts of the year and nobody wanted to lose their vacation days. And of course management look like jerks if they "steal" everyone's time off.

Now, it's "unlimited" (pending management approval), so nobody is "losing" anything when management says no to those two weeks as well. You might get a couple of days here and there, but it's difficult to get a whole week and nearly impossible to get two consecutive weeks.

Just one of the many reasons why I no longer work there.