Yeah I mean bass-line is definitely key when all is said and done and the song is being played; but no one ever wrote a song using a bass or drums. So I guess it's how you define 'important for a band'. For composition of an original, it's gonna be born on a piano or an acoustic.
Bass, drums.... click-track. The writer/frontman sets the bpm variation of the original depending on the mood of the crowd, or how he feels. Everybody wears an ear-piece now b1. They're cheap. The drummer and bassist fall in line. https://www.masterclass.com/articles/how-to-use-a-click-track-when-recording-music
Why do folks turn up music loud?------It's to hear and feel the bass and drums ------that's it in a nutshell. Modern day technology and equalization is protecting hearing now, instead of like in the past.