Interesting thing is a lot of sound deadening practices also apply to insulation. I don’t know if this statistic is accurate in the audio case but it’s not far off.
Heat conduction through studs in an insulated wall also carries sound. A 2x6 plate wall with 2x4 studs on alternating faces (think slalom) helps with both.
There really is just a severe lack of building science education in American construction, because the margins are so thin and it is still dominated by blue collar "man in a van" companies. So you have boneheaded contractors drilling holes into air barriers because that's how it's always been done.