It’s all about demand.
Guys that bought by the box are buying by the case.
Guys that bought by the case are buying by the pallet.
People that never bought anything are buying what they think might be a lifetime supply.
I can note that magazine makers seem to have caught up quite a bit, you can buy AR15 lowers (the key legal part), but ammo makers running round the clock can’t come close to keeping up with the present demand.
(And don’t believe the uninformed speculation that they aren’t making 380 because the machines are tied up for other cartridges. it simply isn’t true.)
I’m sick of buying by the box. But that’s all there is now. When I see a couple boxes here or there, I snatch them up.