Japanese automakers are excessively risk adverse. Last big risk by Toyota was their hybrid synergy drive, which they coasted on for too long.
https://en.wikipedia.org/wiki/Hybrid_Synergy_Drive
https://autos.yahoo.com/ev-and-future-tech/articles/toyota-p...
https://www.motor1.com/news/798173/toyota-chairman-reveals-w...
Which seems strange since Toyota are the origins of JiT manufacturing. I wonder what made Japan go through a period of incredible innovation and then just decide "ok, that's enough".