"As we’ve said before, the current situation is as much a demand shock as a supply shock: demand for Raspberry Pi products increased sharply from the start of 2021 onwards, and supply constraints have prevented us from flexing up to meet this demand, with the result that we now have significant order backlogs for almost all products. In turn, our many resellers have their own backlogs, which they fulfil when they receive stock from us.
These backlogs absorb Raspberry Pi units as fast as (or faster than!) we can produce them, with the result that little of our production volume ends up being immediately available on reseller websites. Where units do appear, bots often attempt to scalp stock which is then resold at higher prices elsewhere."
The fact that they are shipping new PCB revisions of their boards with alternative components (like different PMICs) supports the claim that (at least) part of the shortage was due to supply problems.
> https://www.raspberrypi.com/news/production-and-supply-chain...
Excerpt:
"As we’ve said before, the current situation is as much a demand shock as a supply shock: demand for Raspberry Pi products increased sharply from the start of 2021 onwards, and supply constraints have prevented us from flexing up to meet this demand, with the result that we now have significant order backlogs for almost all products. In turn, our many resellers have their own backlogs, which they fulfil when they receive stock from us.
These backlogs absorb Raspberry Pi units as fast as (or faster than!) we can produce them, with the result that little of our production volume ends up being immediately available on reseller websites. Where units do appear, bots often attempt to scalp stock which is then resold at higher prices elsewhere."
Different perspectives are given in the answer https://raspberrypi.stackexchange.com/questions/139020/why-i...
In particular, the following alternative explanations are discussed (which don't exclude each other):
- industrial customers are given priority
- there are currently deep changes in the Raspberry Pi Foundation happening