Back in the day, King’s KX99 handheld transceiver ruled the roost. It was a big, heavy and solid performer. Today, portable transceivers are far more advanced, but their purpose hasn’t changed.
In lesser aircraft without electrical systems, a portable might be the only option for communicating. Portable transceivers can also bring sizable amounts of utility to your mission, especially when used to fetch clearances, listen to the ATIS before engine start and talking (and navigating, God forbid) your way down during primary radio failure.