Stereotypically, yes, though I know a number of bassists who would say otherwise and who might even get a little upset at your saying so. The saying goes, as with other instruments, that the bass is easy to learn but difficult to master, and though this is a worn idiom it does serve to illustrate how the bass is perceived in a number of rock and pop contexts. The bass can easily and fluidly metamorphose between being a rhythmic and melodic and harmonic instrument, often doing all three within the space of a single song. However, to do so without exhibiting the very seams of the song, one has to be adept at their instrument, almost spiritually taming it.