Is that true in Japan? I recall people sort recycling into many more categories, whereas in the US it is one big recycling bin.

Singapore takes the big bin approach like in the US. Europe has arguably too many bins in some places to be practical (Switzerland, though they charge so much on mandatory regular garbage bags that people still sort out, but it feels like a waste of time)

Since it’s all mixed (which would be nice if done right because it simplifies the process) but so badly that it’s difficult to separate it seems more like a way to avoid clogged rubbish chutes.