Isolation stands: snakeoil?

I understand that turntables are uniquely effected by vibrations due thier sensitivity to that kind of energy. But here’s the thing: most turntables, especially decent ones, have vibration control measures built into them via footers and various construction techniques. So, the question is: are turntable stands / shelves with isolation features actually beneficial or are they just horrendously overpriced accessories for audiophiles?