Earlier quoted context omitted.
Well, yes and no. Its a thing that makes sense for analyzing entire populations, not individuals - same as BMI. But agree there is no such thing as EQ.
If you accept there's no EQ then why not apply the same logic to IQ? They're both based on the same false assumption that you can describe mental capacity with a number. It's not the same with BMI, which is about setting out guidelines for a healthy weight. That is something that's more appropriate to describe numerically.
IQ doesn't purport to "describe mental capacity". It assesses mental capacity and allocates a score. This score is information that can be used to deduce ability, and to the end it serves its purpose perfectly.
Decisions based on IQ is another thing entirely.