As one who bought his first LED flashlight a couple of years ago, a CR2 fed flashlight wasn't even on my radar.....nor was CR123 for that matter. Frankly, I didn't know they existed...so for my customer demographic, they are dead cells.
CR2s are fun though. It seems most of the really cool small run and custom CR2 lights were from years ago and are very hard to get anymore. All the CR2 lights I’ve had were Muyshondts I think. Fortunately Enrique still embraces this size and I do still have one Aeon Mk III, I think it is. The clicky one. I am working on wrangling up some NOS RCR2 lights from Peak. We’ll see what happens!
I'm a fan of the CR2 size and disappointed it basically died. I had a 4Sevens Quark Mini CR2 that was the perfect light to drop in my pocket and watch it disappear. When it actually disappeared, I replaced it with an Aeon MkIII.
IMO, a CR2 twisty is the perfect size to ride loose in a pocket. It's shorter than a AAA and narrower than a CR123. The increased size of the CR123 makes a bigger difference than it might seem.
My Lumitop Picos came in and they make my original Aeon look huge, I thought they would be the size of a small CR-2 but they are very, very small. And quite bright. Nice little pocket or keychain light.
The only CR2 lights I'm aware of in 2023 are weapon-mounted laser sights. (Streamlight makes at least three versions.) It's my understanding that the CR2-powered versions are more popular for handgun-mounted sights because of the smaller size and weight vis-a-vis other kinds of batteries.
Oddly enough, CR2 are still on sale, the price in real stores is the same as that of CR123 or slightly higher, they are also ~ 5 times less (they are in 2 out of 10 battery stores). As it turned out, they are often used in industrial controllers and portable laboratory devices, although it would be possible to use the CR123 and this would not affect mobility (the devices weigh 2-3 kg each)