I disagree the talent was down in the B1G but agree they didn't play as well as teams in the past except for the teams you listed.
I agree. . I think you had teams who had been bottom feeders that turned it around and the optics make it seem like the league was down when it wasn't. PSU and UM didn't have 1-8 NW, 0-9 Neb, 1-8 Maryland to feast on like they did last year. Those teams were considerably better which kind of balanced out the league and PSU, Wisconsin, UM...etc, had to bring their A game every week. Ask Ohio State. Suddenly IU and NW are giving them fits and OSU isn't any worse.
The B1G league dynamic went through a massive overhaul this past season and the trajectory of how this continues will be determined as we go into next season. Indiana, Maryland, Rutgers and Northwestern aren't going to suddenly get worse. I honestly think they will all get better next year so these other teams might not be as bad as the weird season has made people think they are. Maryland is currently #21 in the 2021 recruiting rankings after being #32 last year. The league has just become more competitive in the same manner the SEC has.