It is also possible that Toyota's engineers are not the level they used to be, much like Fujitsu's engineers (who caused one of the largest banking outages ever) or (other company of your choice that used to be a great engineering company but was hollowed out).

Considering the work load at Toyota (it is often referred to as a "black company" by people I know), the level of pressure that is put on their shita-uke companies, and changes in what people consider acceptable work environments, I imagine that they might not attract the same level of talent in 2023 that they did in 1983.