So there's still the unexplained question of why Japanese software is still bad, in 2023. And I think the answer is the language barrier. Windows and Mac dominate the world's computer systems, and the development tools for those environments are English-centric. The translations are lacking or no existent. The struggle of a Japanese developer to make an app is greater than that of a primarily English-speaking developer.
Also, outside of USA/China/India, software developers are still not given much respect or seen as equal to say, mechanical engineers or electrical engineers. So there's little reason for Japanese students to major in software.