Thing is Japanese muscle in R&D have been relatively waning compared to CHN & US. Just take a look at the R&D expenditure, they are stagnant for more than a decade. Relative lack of Human resources also hurt.
Japanese companies have chosen not to go into the production of high end chips, and the state has until now not shown much of an interest in the establishment of state of the art IC chip manufacturing facilities in Japan. It is not as though they are incapable of doing it. When it comes to semiconductor and IC chip manufacturing equipment, as well as particular essential sythesized materials necessary for semiconductor manufacturing and used as components of equipment used in IC chip manufacturing, Japanese companies have a prominent presence. Japanese companies for example dominate the production of DUV and EUV photoresists, Japanese manufacturers produce DUV lighographic machines, and they also produce various lenses and photomasks used in DUV and EUV lithography.
TSMC and Samsung Electronics are permitted by the United States, because of their loyal or not too threatening governments, to use IC chip and semiconductor manufacturing equipment produced by countries that are part of the American alliance system.
In 2019, South Korea had to scramble for alternate additional suppliers and begin the implementation of a programme to greatly improve and increase the production output of semiconductor and IC chip manufacturing equipment and materials after Japan placed restrictions on exports of such things as hydrogen fluoride etching fluid and photoresists, following a spat between Tokyo and Seoul on a ruling that South Korean courts deemed that Japanese companies had to pay compensation to the victims of forced labour by such companies during and prior to World War 2.
China, unlike Taiwan and South Korea, as the Trump started trade war proved, must produce or at least have the capability of producing every single product of the supply and tech chain when it comes to semiconductor related industries. EVERY. SINGLE. PRODUCT.