Doesn't work in hilly cities. That's why San Francisco has trolleybuses too (and the historical cable cars, but those are more for tourists). They do have light rail where it does make sense though.
I don't quite remember what they're called but in the UK there's both old mining trains and old cliff trains/trolleys that use toothed wheels and toothed tracks on the hill portions to go up/down hill with little issue, obviously it's only safe for some gradient, but still with the right gearing it would be of possible
This. Trams are so much nicer, carry more people, way less maintenance cost and the tracks look so good if grass grows between it, also I don't get motion sickness on them. You don't even need any asphalt for them which is expensive to maintain, looks worse than pretty much anything except maybe a literal pile of garbage and heats up the surrounding area.