In the words of the immortal Admiral Ackbar: “It’s a Trap!”
There’s no such thing as “unlimited time off” unless you own the company. No job, no matter how forward-thinking and generous, allows you to just decide that you want to, say, take off six months at a time every year. They will, of course, fire you, if you have a job that really needs somebody year-round. (They do this often enough when it’s illegal (e.g. Military Reserve leave), so of course it’ll happen if it’s perfectly allowed.)
A more accurate name would be “management-discretion time-off” If I was an employee, I’d want “with a minimum of X days per year” added to that, to stop a penny-pinching manager from preventing employees from having a life.