[fallat]

Pretty much this in a vague way. Obviously not exactly as the comment is written, but yes, it should be measured in the actual usage of the tokens.

[redox99]

One decent metric are the fees[1]. Basically how much money people are actually spending to use the cryptocurrency.

Raw usage (as in number of transactions) is meaningless because it can be trivially manipulated by wash trading if the fees are super low (typical of a barely used chain).

[1] https://cryptofees.info/