I like having accrued annual leave and sick leave for the exact reason that they are tangible numbers that I can reasonably say I own. If it was "unlimited" as

I like having accrued annual leave and sick leave for the exact reason that they are tangible numbers that I can reasonably say I own. If it was "unlimited" as you say, it seems more like the company or team owns them, and your expected to conform to expectations on their limited use.