For one, Nebraska has the benefit of not sharing fan allegiance with another school. Iowa shares its primary market with Iowa State. That has to make a difference.
Iowa will be in the mix, but they cannot regularly compete for top level talent. And there are far more schools situated like Iowa who will searching for these same younger transfers and recruits. Ohio State may not have bottomless coffer, but it is far deeper than Iowa's, and they, and other schools, will always be at least a step ahead of Iowa on that front.
One thing that Iowa has going for it over many others is a solid program culture. It's considered boring and antiquated by many, but it helps distinguish them for the potpourri of similarly situated schools. And recruits/transfers (and their families) are attracted to it. Like it or hate it, Hayden and Kirk built this and Iowa would be wise to find their next coach who is of the same mentality and attitude. Nebraska may rake in more money, but their culture that was cultivated by Devaney and Osborne is dead, and they are barely living off the memories of the past. That's my take on it.