Whether or not you listen to music is a debate for somebody else to have.
I can definitely attest to the value of sound dampening by whatever means. If you wear ear plugs (or headphones, or whatever), you will be bothered less by the very high SPL of most riding in traffic (especially at higher speeds). You’ll be able to concentrate more on what’s around you, and you’ll suffer less hearing fatigue (loud noises for long periods of time do wear on you). Everything is loud enough that even with -10dB to -30dB ear plugs you’ll still hear everything you need to hear.