Noise isolation is mainly about adding mass. Thermal insulation is mainly about creating a continuous skin and filling the void with something as close to a vacuum as you can get.
Home insulation doesn’t work by making walls close to vacuum. You insulate walls by stuffing more (but not too much) of stuff into them, not by pumping out air or anything silly like that.
Vacuum is a great insulator, because it blocks two fastest ways of heat transfer, conduction and convection, leaving only radiation. House insulation tries to do the same thing: filling up the wall with fluff blocks air from moving around, which impedes convection. Fluff itself is made from materials of low thermal conductivity, like cotton or mineral wool. At the end of the day, though, filling walls with fluff makes them less like vacuum, not more.
Vacuum is a great insulator, because it blocks two fastest ways of heat transfer, conduction and convection, leaving only radiation. House insulation tries to do the same thing: filling up the wall with fluff blocks air from moving around, which impedes convection. Fluff itself is made from materials of low thermal conductivity, like cotton or mineral wool. At the end of the day, though, filling walls with fluff makes them less like vacuum, not more.