In Osaka, Hankyu Railway (granted, a commuter train operator, but most if not all commuter trains service in Japan runs like subway) still runs multiple 3300 series, manufactured in 1969. They (the 3300's) actually also run into the Osaka Metro system, and you cannot really tell it's built almost 50 years ago.

And CTBC... Most of the newslet says that one of the problem with old system is that it cannot accurately tell where the train is... Well, I know NYC signalling system is ancient, but not being able to tell accurately where the train is IS NOT the problem. Most of the Japanese lines (including various subways) still run on block system (though sometime with a block length of just 100m). Communication-based system is in place on some line, though, but mostly for lightly-traffic line to save on signalling equipment cost.