Musicians: How important is the bass player in a band?

I was talking to my friend who is a bassist and was surprised by something he said about everyone in the band looking to the bass player. I can rarely even hear the bass line when he plays so it struck me although I didn’t question him. Is that true in your experience and if so, for what? The rhythm, the timing?

Just curious to hear some opinions from other musicians or knowledgeable fans.