Looks like ESPN doesn’t think highly of one conference.
ESPN’s Football Power Index (FPI) ratings for the preseason have strength of schedules attached to for every team, and per the ratings, several contenders are falling short in terms of quality opposition. Those contenders? Ohio State, Penn State, and Wisconsin, who rank 52nd, 61st, and 63rd out of the 65 Power 5 teams in strength of schedule by the FPI metric.
Despite all three of those teams being in the Top 10 in terms of team quality by FPI, it looks like the rest of the Big Ten is getting penalized, thus resulting in the teams ranking lower in schedule strength than everyone else.
For example, Ohio State plays Oklahoma, Michigan, and Penn State this year, but it looks like their games against Rutgers, UNLV, and Army bring them down more than those other games benefit them.
For the full FPI stats, you can go here.