Most ski areas that I know of have seasonal locker rentals, at least the ones around here do
I had one in high school pre-license to drive, it was great. I had all my gear in my locker (even boots and gloves sometimes, that started to smell). I would pack my pants and socks with me to school, after school I'd take the school bus right to the ski area. Parents would pick me up later at night (5 minutes from home). Good times.
Also made a convenient stash space if need be. I remember this one time when I was ~15, the cops came up to the hill about stolen gear or something. This one kid had two cans of beer, well not really it was Beast. He freaked and asked if he could stash them in my locker. I guarded those two cans of beast for about a week and a half like they were gold. Looking back, I was probably guarding about 75 cents worth of beer, but to us that was like gold. Ahhh youth.
As I got older, tuned more and traveled further to ski, the locker became more of a hassle than a convenience. Last minute day trips to other mountains are kinda tough when you have to wait for the mountain to open to get your skis. They gotta be great for families with small kids though.
I'd say that more smaller, season pass driven bump hills would be more likely to have seasonal than major resorts. My current bump has so many locker holders they built a separate "bubble" thing with just lockers in it.
I don't think I've ever seen a full size ski locker available for day use.