On a motorcycle you need hearing protection due to wind noise, but good plugs will filter out the louder noises, not so much important ones.
Do you have a source for this info? It contradicts what I've read about the subject.
Safe cycling is all about vision. If you can't see it's safe, it's not. It isn't simply seeing imminent threats but predicting them e.g. identifying drivers that aren't paying attention and where a car could suddenly emerge like blind turnings, car doors, pedestrians and such, and countering with appropriate caution / road position.
If you find noise useful, IMHO it means you aren't sufficiently aware of your environment.