If there was no such thing as decoupling we never could have detected and observed gravity waves. The only challenge for decoupling for audio is how many directions 🔜 🔚 🔝 you can decouple from and how low a resonant frequency Fr you can achieve for each direction. My airspring Nimbus of yore, for example, decoupled in all six (count em!) directions with Fr as low as below 1 Hz. The lower you go the higher you fly.
In other words decoupling is not (rpt not) synonymous with damping. Damping techniques on the other hand 🖐 cannot affect extremely low freqjencies of vibration. That’s why mass-on-spring devices must (rpt must) be used for vibration in the range 0-20 Hz. You can also think of iso devices as anti gravity devices, if that helps. By the time you get to 20 Hz you’re already 95% effective. So, where’s the beef? 🍔