Yes, that works great in dense cities that can justify running a train every 5 minutes. What sets Switzerland apart is that it can offer reliable, punctual service to tiny mountain villages that may only have a couple of trains a day, but those trains are carefully scheduled so that you can get there from Zurich or wherever with an absolute minimum of waiting around for your connections or fretting if you'll make it. (In the unlikely event that your train is a few minutes late, they will hold the connection.)
> Yes, that works great in dense cities that can justify running a train every 5 minutes.
Indeed, here in Singapore during peak hours the trains come even more often. And that's not counting all the trains in a station, just the ones from one metro line that come and go on one platform in one direction.
Every once in a while, they are upgrading the signalling systems, so that they can squeeze even more trains in.