Except LTV is unhelpful because it adds this extra "exchange value" thing which is not actually the price, because you can end up with stuff that nominally has an exchange value that exceeds what anyone's marginal utility would indicate that they'll pay for it.

In the case of stable commodity markets with a slow pace of technological improvement and ample competition, MTV and LTV give the same prediction of price.

When LTV diverges, it might be an indication that there is some exploitation in the market. Or it might indicate that there have been changes in productivity and there's existing stock. Or that something isn't cool anymore. Or any number of other things. When it doesn't diverge, you still might be foisting externalities onto others (e.g. by degrading the environment) and need urgent legislative correction.

It basically adds an extra variable that is very difficult to calculate accurately and which has dubious purpose.