> ... giant gates ...

There's a big difference in antisocial behaviour and visible mental health issues between Tokyo and San Francisco.

"San Francisco’s BART found that systemwide crime fell 41 percent after new gates were installed. Even more impressively, across the ten stations with the most corrective maintenance needs, staff time spent on in-system maintenance fell 96 percent, which suggests that fare evaders also cause most unreported crime, like littering, vandalism, and graffiti."

https://www.city-journal.org/article/transit-crime-fare-gate...