Basically: greed (lower overhead from larger orders) and more greed (chasing large companies, I guess in the hopes of securing fat, profitable long term contracts, or maybe donations, or both) and probably trying to cut out distributors, too (the "email us and we'll work something out" he kept telling everyone), again because of greed.
Raspberry Pi foundation burned their brand image and good will to the ground. Everyone has moved on to using clones, other ARM devices, embedded systems that have AI accelerators, old PCs and laptops, ESP32's, and so on.
Half the shit people were doing with Rpis were better suited for things like ESP32's anyway.