If you had a technical approach that could reduce tunneling costs, that would be great and would have lots of potential benefits. But human transport is not one of them. Even if the you could build vacuum tunnels that could shoot pods safely at high speeds, the capacity would not be high enough to make the slightest difference in mass transit.

If you could cheaply tunnel, the transit application is to extend, expand, or build more subway lines. Not develop super-high tech tubes that can transport small handfuls of people at a time.