I disagree with the OP. Michigan is a good team and would probably do well if they were matched up with an ACC, PAC 12, or BIG 12 opponent in the playoffs.
However, the SEC is obviously the best conference. This bowl season shows how tough the conference is from top to bottom. You have lower tier SEC schools, such as Kentucky and Arkansas, destroying the best teams in the B1G. South Carolina beating North Carolina. Iowa, Penn State, and North Carolina were all top 10 teams at one point during the season and got destroyed by lower tier teams in the SEC. Iowa played in the Conference Championship game in the B1G.
Alabama, Georgia, Ole Miss, and Texas A&M were clearly the four best teams this season. Ole Miss would have beaten Baylor by three touchdowns if Corral didn't get hurt. Kentucky, Arkansas, Auburn, Florida, Tennessee, and L.S.U. would probably make the playoffs if they played in the B1G, PAC12, or BIG 12. Probably even the ACC. Mississippi State and South Carolina would probably be ranked in the Top 10 if they didn't have to play a SEC schedule this season.
How many B1G teams do you think would be bowl eligible if they had to play and SEC schedule? Maybe Michigan and Ohio State? Maybe? There is no way that teams like Michigan State, Iowa, Wisconsin, Purdue, or Rutgers would be bowl eligible if they had to play an SEC schedule. Most of those teams would be lucky to win more than 2 games if they were in the SEC. How many players on their rosters were recruited by SEC schools? Who could Michigan State, Iowa, or Wisconsin beat in the SEC aside from Vanderbilt? I doubt Purdue, Rutgers, or Maryland would even win a game in the SEC? Nebraska? Illinois? Northwestern? I am sure I am even forgetting some teams in the B1G who are even worse than them.
The SEC has dozens of players sitting out of bowls because they are going to be first round draft picks and they are still dominating the bowl season. You don't see that at schools from other conferences. Ohio State is supposed to be full of SEC talent but they barely beat a short handed Utah team and might not have won if Utah's QB didn't get hurt. Ohio State would've been beat easily if they had to play a SEC team, same as Iowa, Michigan, and Penn State.
Stroud and Hutchinson were Heisman finalists, but they don't even start at half the schools in the SEC. Justin Fields couldn't even start in the SEC and had to transfer to the B1G because he could get playing time at Georgia. How often do you see a player from the B1G transfer to an SEC school? Never, because they aren't good enough. (Maybe good enough for Vanderbilt but a B1G player probably wouldn't be able to get accepted in Vanderbilt anyways). Meanwhile Fields goes from bench warmer to Heisman trophy finalist by transferring from the SEC to a B1G school. Same with Jalen Hurts transferring to OU. None of those players were good enough to play in the SEC. (Why do you think Lincoln Riley took the job at USCw? Because he knew he didn't have the talent to compete in the SEC?) Do you think Fields and Hurts are at the same level as Joe Burrow and Tua Tagovailoa? Of course not and that is the difference between the SEC and other Conferences.
Meanwhile you have a running back transfer to the B1G from the ACC and break records against B1G. What he do in his bowl game? Nothing... because he wasn't playing against B1G defenses. Iowa was supposed to be a "great" defense but they almost gave up 200 yards receiving to Kentucky's 5'6" receiver. Imagine how many yard the 5'6" Kentucky recover would have if he played B1G defenses every week.