destiny, a bass line doesn't need to be "groovy" or "funky" in order to be effective. some of the greatest bass players in rock history played most songs with slow pacing. people like to bring Flea of the red hot chilli peppers as an example of a great bassist, but it saddens me that he is mainly praised for his virtuoso and funky songs and not his solid pieces.

here is Flea's funky bass in "Cant Stop" https://youtu.be/ZflBTTNjCsE?t=37s

here is Flea's slow yet beautiful bass in "Under the Bridge" https://youtu.be/PE9gERFNu88?t=9s

note that Flea doesn't just repeat the guitarist, he is playing a different melody that excellently connects the drums with the guitar.

another great bassist is Roger Waters of Pink Floyd. here is a slow "boring" piece: https://youtu.be/5_SUiiOJtL8?t=10s Waters composed this bass line after Gilmour was finished with the lap steel guitar, and electric guitar line. note how it is completely different yet they follow the same "waves".

here is a repetitive piece from Waters: https://youtu.be/bnC7TdkRnP4?t=7m55s it is a very simple bass line, however the entire section of this song is built upon it.

and of course there was one Cliff Burton, who sometimes used distortion to make his bass sound like a weird electric guitar https://www.youtube.com/watch?v=fM0cdYVNXB8 but most of the time he was an excellent metal bassist who supported the rythm guitar. he also has great riffs like this https://youtu.be/-qYqi-EMErU?t=3m56s

so, in rock music at least, a bass player doesn't need to be flashy and go crazy with his bass. a bass player is like an engineer who has to make sure that the creation of the guitarists (architects) doesn't collapse into pieces. sometimes he does it the boring way, sometimes the funky way - but one thing for sure: bass players are not just bad guitarists who had to switch an instrument.