Personally I do not know why there is a digital chip shortage.
Hi Jeff --
I got curious about this, too. There are several factors as the world is a complicated place.
Many integrated circuits (IC) are made in China. The Chinese COVID-19 protocols have slowed production.
Some manufacturers deliberately slowed production anticipating a global business slowdown. Now it's taking time to ramp up, again. Semiconductor manufacturing is not a case of "let's put a few more people on the nightshift." It takes time to restart fabrication lines. And building a factory -- it takes years. Thus, factory capacity is pretty much fixed in the short and medium term. Product lead times are out to 32 weeks.
Many ICs are relatively general purpose (like memory), but some ICs are special purpose like the digital to analog converters (DAC) in audio products. There were two significant factory fires: one affecting chips for automobiles and one affecting DACs. In the first case, Toyota (and others) got hit hard. In the second case, Yamaha and other vendors using audio chips like DACs got hit hard.
Yes, manufacturing of special ICs can be that specialized and localized! The Japanese authorities have only recently allowed the DAC factory to rebuild; it was off-line for several months. If a company like Yamaha needs a specialized chip for a product and the company cannot get the chip, it must wait even if it has all the other parts in hand.
Throw the global shipping mess on top and it's a disaster stew.
Hope this simplified explanation helps -- pj