ISU's academics would "qualify" for B1G (and PAC and ACC), but not be "impressive" or "elite".
Bit of a rant, but I don't love the academic rankings as they are done, esp the USNWR ones. It's far far far too heavily weighted on dumb things like how many applicants you deny. A school like ISU that has published minimums for acceptance -- well hardly anyone who can't make those will apply so the denial rate is really low, by design.
Another problem is opinions of academic bigwigs. Those opinions are relevant, but the Altimore report shows you how incestuous the Alliance schools are with personnel, so guess what? That's a super self-serving opinion circle.