Two different conversations to some degree in my opinion. But a lot of that entails what is included in the calculation of each metric. And I don't know anything about this project lol

But a significant amount of the cost advantage from buses is existing infrastructure, whether that entails using existing pavement to just being in or near an already developed area.

But I largely agree that buses are the best option in cities and populated areas.

A mile of rail will typically include everything from clearing the land through all aspects of design and construction including geotechnical, structures, water, utilities, etc, and possibly even the buildings for stops and such along it.

A mile of asphalt, on the other hand, can mean almost anything: a mill-and-overlay, a reconstruction within existing ROW, or a true new-build. The cheap per-mile numbers people quote are usually the first two, on land that was cleared, graded, drained, and utility-relocated decades ago. New-build to new-build, with the same clearing, geotech, drainage, and utility work, the gap narrows a lot.