Having never been to Japan, I don’t dispute anything you say, and as an American I definitely agree those things sound great.
However I do think it’s fair to point out the existence of women-only train cars in Japan, which I believe exist at least in part due to groping. Seems like YMMV depending on gender.
One thing that occurred to me recently is that Japanese book stores will wrap your books in paper to protect one's privacy while reading on mass transit. There are still some bookstores in Taiwan that still preserve this tradition as well.
There's quite a lot of interviews with western women on this subject on YouTube. Can't remember the channel.
I felt so incredibly safe in Japan and I don't remember even seeing a cop. As an American, that felt crazy to me for how large those cities are. I had some expectation of that but it still surprised me, particularly in the touristy nightlife districts with the street drinking.
Obviously seems like there might be some downsides to the culture that leads to this.
You probably didn't realize what to look for. There are quite a lot of kobans (https://en.wikipedia.org/wiki/K%C5%8Dban), especially in busy locations. Seeing police patrolling around the area is rare sight from my experience though (disclaimer: Experience strictly as tourist).
I mean, groping on the subway is a problem in New York City too. We just close our eyes and plug our ears while singing "hire more cops". A women-only car would be most welcome.
Yup, and it's always "impossible" to add doors, when Tokyo added them over the course of a decade with no problems and significantly more complicated through-running schemes.
However I do think it’s fair to point out the existence of women-only train cars in Japan, which I believe exist at least in part due to groping. Seems like YMMV depending on gender.