I know this has been covered in previous threads somewhere but here is a brief attempt at an explanation.
Hodgdon does not manufacturer any powder at all. They are just a distributor of powders they have manufactured elsewhere, mostly in Australia. Here is a grid showing the conversion of AUS powders to US powders:
It is a special note here to see that Retumbo is an AUS powder and is subject to shipping laws made by both AUS and the US which limits the amount of powder delivered to the US from AUS. It comes by ship in containers. That explains why Hodgdon states 'late 2019'. Some IMR powders are made in Canada, while Goex is still made in Louisiana. Winchester powders are made in Florida.
It is the maritime shipping laws which are the limiter for the amount of powder shipped from AUS. But what has happened is they have created a self-perpetuating hording cycle which now occurs with greater frequency because of the lack of stock from the manufacturers. This also serves to allow for consecutive price increases due to a lack of product and hording. Supply and demand. And it's not just powder but now brass has been in that cycle for the last year+ at least. Norma was the biggest offender so now I order brass by the pallet.

Being egocentric, we all want to get ours and don't care what happens to anyone else. I'm not being critical.

We continue to reinforce the cycle while the manufacturers simply go to the bank.
I certainly don't have a solution. There are several powders and cartridges I need to keep the business running so when I'm caught short I place back orders, hoping to capitalize on several suppliers being able to deliver larger qualities at the later date.