Simulcasting is most often found in metropolitan areas. It is a way of achieving radio system coverage in larger concrete buildings at a lower transmit power per site.
With lower power transmitters, radio frequencies can be re-used without as much geographic separation. For example with a high power single site, there might need to be 100 miles of separation between users of 854.4875. With lower power simulcast, that distance could drop to 50 miles. One of the bigger challenges in communications is the lack of frequencies, so simulcasting can help that.
I would agree. There are a ton of county wide simulcast sites for large areas and to help with coverage in areas shadowed by land from a single site. More coverage for the same amount of frequencies is always desired.I would not [never] rule it out, in Non Metropolitan areas