One of the issues with 'unlimited' vacation is that when you leave your employment you don't have any carryover anymore so the company doesn't pay you for unused vacation.
I know this because my wife worked at a "unlimited time off" company, and even though she gave them a heads up before accepting that she took a month or more vacation a year, when she did that they turned around and had an all hands about it was being abused.
My opinion on unlimited time off: if I can't say "I'm taking a year long vacation" you need to give a finite limit. Nom company would agree to this because unlimited time off is deliberately to avoid liability for earned income.
I’m not against untracked time but it needs to be implemented in concert with hard minimums and a culture that is accepting of people taking time off.