I know MS VS Code has the Japanese locale extension, however it's mandatory for the people not familiar with all English editors, also not familiar with the families of VS Code, OSS Dev, etc.

I'm both of them. Only such factor can make the people avoid the IDE of Project IDX.

Critical: Why IDX, Code OSS, cannot change Display Japanese Display For me, I'm not familiar with MS VS CODE the families Enable to Change "Display Language", Japanese for me, that VS CODE can realize very easily