It's mixed. From my personal observations the more junior folks and the people less up to date on the discourse around unlimited PTO are happier, but people who are aware of the knock-on effects on company culture, pressure to deliver, etc. are unhappy.
I wish I could get unlimited UNpaid time off. 90% of the value I create at work happens during initial factory line bringup and the last few weeks before shipping something. I'd go hang out somewhere cheap and live like a king most of the year