You are merely ignoranct. Silencers are NOT silent. They massively reduce the noise signature. I have terrible hearing loss because silencers (and suppressed guns) are unnecessarily expensive in this country. Suppressors (actual name of silencers) are excellent for teaching new shooters. Cuts the noise and felt recoil.
I’ve played MGS, and have actually heard some sounds from suppressors, so yes, I do in fact know about them still making sounds. Suppressors, that’s what their names are.