The lead times for the STM microcontrollers have gone way beyond unreasonable. "730 days" I think is a polite way of saying "we may never supply you with this chip".
Normally, this allows every designer to pick the most suitable part and have the lowest total BoM cost. However, in today's challenging supply/demand environment, the total number of unique parts that must be manufactured must be causing a huge problem.
I may be way off here but my observation is that chips that are very configurable are the hardest to purchase. For example, the STM32 series have something like ~3000 SKUs ( https://www.digikey.com/en/products/filter/embedded-microcon... ).
Normally, this allows every designer to pick the most suitable part and have the lowest total BoM cost. However, in today's challenging supply/demand environment, the total number of unique parts that must be manufactured must be causing a huge problem.