Playing More Instruments
I believe that if you’re a musician, you can play any instrument. You may not be as proficient on other instruments, although you can still be musical with these other instruments.
I myself enjoy playing other instruments apart from the bass. I think it’s good to get experience with these other instruments, because when you jam with people who play them, you can have a better understanding of how they play. If you can learn a basic drum beat, you can hear how your instrument can fit in with the drums. Or if you can play some chords on the piano, you can hear what chords might sound better in a certain location on the piano.
Another reason it’s good to have experience with other instruments is that you can write songs and parts for these instruments for someone to play. It may be easier to write a drum part for a drummer if you know a basic drum beat and fill.