Establishing a new bus service in an area where public transportation had not existed must be indeed much cheaper.
However it is impossible for the operational and maintenance costs for a bus service and for the roads on which the buses go to be cheaper than for an electric streetcar, unless some prices are fake.
It is true that I have seen enough cases where electric streetcars have been replaced by buses, but I cannot see other explanation except bribes, because it was extremely visible that the buses were more expensive, both because of the fuel consumption and because of the much more frequent repairs both for the buses and for the roads.
It's interesting, in San Francisco, the streetcars got too heavy for the old tracks so they replaced them with about 4 feet deep of concrete. That is actual infrastructure and not "fake". (along with all the stops and handicap ramps and etc. obviously, a paved street is going to exist either way.)
Bribes and the mafia may have been a factor[0], but that's how American cities do things.
However it is impossible for the operational and maintenance costs for a bus service and for the roads on which the buses go to be cheaper than for an electric streetcar, unless some prices are fake.
It is true that I have seen enough cases where electric streetcars have been replaced by buses, but I cannot see other explanation except bribes, because it was extremely visible that the buses were more expensive, both because of the fuel consumption and because of the much more frequent repairs both for the buses and for the roads.