My theory is this..... it's not the availability, it's the price.....
We equate very high prices with availability
There are plenty of online places like that KYGUNCO to order caps, my local places have caps , Powderinc has black powder , it's out there , but people used to paying $5 a tin or $20 per lb are like "I'm not paying $15 per tin for caps that's gouging!"
So that equates to shortage, to them.
The same for ammunition. My local Dunham's has enough 5.56 to outfit a Battalion. All the ammunition I could ever need is available , it's just 50- 75 cents per round now. Online sources have lots of 1000 round cases of common calibers available if you're willing to pay. There's no shortage
Any one of us can currently get anything we need to shoot our guns
We've all seen "shortage" several times.....who remembers the Obama panic of 2008, or the panic after that when people were on the news leaving gun shops with 7 AR15s .
And there wasn't a round of anything, anywhere. Maybe if you got lucky you could score some 20 Gauge birdshot or .357 Sig or some other oddball manure.
We haven't yet seen the next "shortage " so if someone needs to drain their savings account to buy ammunition or caps, I guess do so now
I'd rather spend my money adding more peanut butter and powdered eggs to my stash