What is the point of bass guitar in rock n roll?

I have always wondered why bands even have bass players because you
never hear them. What do they even do? To me it seems like the
instruments you actually hear are more important than the ones you
don't, since the whole point of music is about hearing things.

Some people say that the bass player changes the sound of the other
instruments and that they would sound bad without them. however this
obviously untrue since you can hear guitars, drums, and singers do
their thing completely by them self and sound fine. That begs the
question, what is the point of a guy playing a bass guitar that no one
hears or cares about and just plays the same booming note over again?
I listen to TONS of music. I love rock n roll and i garentee i know
much more about rock n roll than anybody of you who tell me i don't
listen to music and think they actually know things about music.