Something like unmetered or untracked is probably a better term. Of course, it's not literally unlimited.
It really does need to come with a top-down culture of taking vacation which a senior former Netflix person told me was the case there. (Though I've also heard it varies by team.) It also isn't great if you want to switch around jobs a lot because you won't get any payout when you leave.
Though you do have issues with people taking vacation even in a more traditional system. In a prior job I took some month long vacations and there were some coworkers who were incredulous that "I could do that."
