If I'm playing Jazz or Funk I typically play without a pick, makes it easier to slap/pop If I'm playing "Jam" music without a rhythm guitar player or without a drummer, I like to add a pick for a more percussive sound. My preference is without a pick
Song demanding. There's no right or wrong: just get the job done. And I hate to limit myself. Been playing 35+ yrs.
I've played guitar since a teenager so playing my bass with a pick is all I know. Most players I've been around never used a pick though when they played bass.
I have never used a pick when playing bass. I just like the sound better and it just feels natural to me.
I conceptualize it a certain way for guitar - and really, a bass is another kind of guitar. I have some instructors who might say that it depends on what kind of music you're playing, for example jazz. When I took jazz lessons, one of my instructors had a negative view of a sort Dave Matthews-y take on jazz that included playing chords with a pick! But my personal preference is to play with a pick.
Been playing bass off and on for about 40 years. Played most genres from orchestral to rock musicals and from the 50'sto the 90's. Pretty sure that I've never used a pick.
No pick here (for bass or guitar), but I gotta admit if I could sound like any bassist it would be Chris Squire, so I'm constantly thinking I went down the wrong path :/