It's a multi pronged situation: Military contracts, politics creating multitudes of new shooters, riots and civil unrest causing people to stockpile, reloaders laying in whatever we can find. Call it preparation for future calamities, hoarding, replenishing supplies, whatever. It is a problem without an easy solution in the forseeable future.
I can understand the shortages. Too much demand and not enough supply--for now. Hopefully it will even out soon and components and loaded ammo will start showing up. It is frustrating. I have had small pistol primers on order since March, all rifle and pistol components with no source available. All out of stock and most not available through backorder. I reckon patience and limited shooting is the watchword for now.