I guess it depends on the size of the store. Around here, every grocery store has their liquor cabinet locked up. Except Trader Joe’s, which only opened last year, and replaced a Rite Aid that used to be in the same location (and of course, had lots of stuff locked up).

Now, Trader Joe’s doesn’t sell most items that other stores keep locked up besides liquor. But they don’t lock up their liquor either (or anything else for that matter). However, it’s just a tiny shelf and conveniently placed right across from the manager’s desk, so pretty much always within direct view of a team member.

Also, they probably have almost the same amount of staff as the Kroger across the street that’s 4x as big, so I suppose what you say IS possible, but you do pay for it with a much more limited selection. Trader Joe’s has exactly one of everything (their store brand), and if you don’t like that, you’re SOL. Regular supermarkets have way more choices, and they’re paying a lot more in rent to afford the space to stock all of these items.