When I worked at Uber engineering which had unlimited PTO, I took between 6-8 weeks of PTO every year. Most years was at least 6, but one year I took 8. No one batted an eye. I think it all depends on company culture or maybe team culture.
I would never work for a company that denied me a PTO day, even if it was a single day. I would never irresponsibly take PTO but I would also make sure that I took at least 4 weeks off per year no matter what. The secret is taking 1 week off per quarter, and then another 2 weeks off during Christmas. That automatically brings you up to 6 weeks.
But make no mistake, unlimited vacation is a way to keep PTO off the books as a liability. In California you cannot lose PTO that you have accrued. They can stop accrual however once you reach a certain level. Once you max out on accrual, you are giving the company money, which is stupid so it's important to consistently take PTO.