Train Rome to Perugia? Or car?

Direct train from Rome to Perugia
About 2.5 hours
14-16 euros

Cheaper, faster and easier than a car

https://www.trenitalia.com/content/tcom/en.html

Lots of trains all day - the cost 15 euros, more or less.

We wanted a car while there so picked it up at FCO.

Time of travel is not that different between train or car. About 2.5 hours.
Whether you want to take the train or drive depends on whether you need a car while in Umbria.
If you don’t need a car while in Perugia, then the train makes better sense. If you need a car while in Umbria, then you can either take the train and rent a car in Perugia, or rent the car in Rome and drive to Perugia from Rome.