I can't shake the feeling/belief that lie detectors are extremely effective (as in, far more than things we consider to be very impactful like eye-witness testimony).

I base this solely on two things I observe: first, if lie detectors were real and effective they would revolutionize justice and that would have a horrific effect on the billionaire class and for-profit criminal justice system. Second, despite them being all kinds of popular a few decades ago in popular media, etc., they are largely cast aside today and rarely mentioned.

Should you ever force someone to take one? Fuck no - you shouldn't make anyone testify in any capacity.

But should people be allowed to voluntarily take them if they work? Absolutely. Think how many people could be credibly acquitted with a 10 minute low cost test. "Where you in the city yesterday? No."

Obviously they're not 100% perfect. But are they better or equal than other forms of evidence (i.e., eye witness; photographic) that we allow as evidence today?

Or are they actually bullshit? I've not looked deeply into this issue so would love to have my belief affirmed or changed.

EDIT: Really appreciate the responses I definitely was not considering the other possibility: that they have been known to be bullshit for a long time yet still propped up by law enforcement for as long as they can.