Yeah, in the west people switch studios, knowledge transfers happened all the time, tools of different studios were somewhat similar. Almost non-existence in Japan, expertise were kept within. Learning new things takes time, when veterans have quit left and right, new guys had to learn from zero.

Japanese devs got burned-out from working 20 hours a day, 7 days a week, for 6~12 months to ship a game. Veteran programmers, artists quit. One reason why ps3-era Japanese games were lackluster. The industry restarted with new people then, getting results starting ps4-era, now reaping it again.