I agree. It also makes it harder to compare companies because it moves an explicit benefit “X days PTO per year” to a vague one “well, it’s whatever days your manager feels like approving”.

As a manager I’d also hate this - it’s another thing that I would have to keep track of and weigh. I don’t want to have to discuss with people about how much PTO is okay! That’s something somebody else should decide!

If a company really wants to give people flexibility they would give X days of paid vacation plus as much unpaid as your manager will approve. Best of both worlds IMO.

Addendum: The company I work for has a “once in a lifetime opportunity” policy where if you want to do something special, like climb Everest or take a cruise around the world or whatever, they’ll work with you to figure out how to make leave work for it. It’s not actually once in a lifetime either, the policy says once every five years or so. I like that idea a lot, even if I’ve never used it.