Well yeah, that's what a modern public transportation system looks like - I know that's unusual in the US, but if you look at other places, e.g. Europe, you will also have buses, trams/light rail (with tunnel segments and heritage services for tourists) and minibuses/neighborhood shuttles in most bigger cities. The only thing that sets SF apart is the cable cars - and having both a fully grade-separated metro (BART) and a light rail system with tunnel sections (Muni Metro) - usually in cities with a "full metro" the light rail is a tram without tunnel stations.