Nope, it's not another merger or anything Amazon has done, but these two huge issues are affecting everyone in the publishing chain. And they are all thanks to the global pandemic.
1) The first issue is the supply shortage. All companies are suffering this, but for publishing, the printers are having trouble getting paper.
We went through a similar paper shortage in the '90's. That coupled with the collapse of a major distributor triggered a rise in prices.
This time, the companies producing paper are looking at their own supply shortage of raw material thanks to lockdowns, illness, and death from COVID-19. Then they have their own problems staffing their facilities.
Unfortunately, shortages drive prices up. I use Ingramspark for printing my own books. The CEO of Ingram sent out a notice that they are initiating a 6% increase in printing costs because they're having to pay extra to get paper. This means I, as a publisher, have to increase the price of my books to cover my overhead. It sucks the big one for my readers. Since I use POD printing, the cost is already higher than a Big 5 paperback.
2) The second issue is staffing. Just like the factories that produce pulp for the paper mills and mills themselves, there's a major shortage in employees. There's a combination of factors: deaths from COVID-19, people with health issues thanks to long COVID, quarantines because of sick family members, employees forced to find other jobs do to shutdowns, etc. Ingram is facing the same low staff problems as every other company, which was why the CEO told his own customers to get their orders in early.
Ingram isn't the only printer having these issues. The shipping companies are also having staffing issues. Ports don't have enough people to unload ships coming into the U.S. There's a shortage of truck drivers, warehouse workers, and delivery drivers.
The Big Five are especially sensitive to these problems. As a result, even if an author's book is selling like gangbusters, the major publishers aren't bothering to reprint those books. So if a bookstore owner has a zillion requests for whatever book is the new, hot thing, they can't get it!
In a way, I'm lucky being a small cheese publisher. I have some print sales, but not enough to start fretting about the shortages. Yet.
However, I will have to adjust my calculations for my proposed Kickstarter in case the paperbacks become a big reward item that backers want.