According to Simple Rating System (SRS), 2019 LSU has the highest SRS of any SEC FB team in the last 40 years.

Highest SRS by a SEC football team since 1980

1. 2019 LSU- 25.80
2. 2016 Alabama- 25.62
3. 2008 Florida- 25.37
4. 2018 Alabama- 25.29
5. 2012 LSU- 24.51
6. 2011 Alabama- 24.44
7. 2011 LSU- 24.27
8. 1980 Alabama- 23.80
9. 2015 Alabama- 23.72
10. 2009 Alabama- 23.69

And 2020 Bama's SRS is basically the same as their team from last year although it'll definitely shoot up if they beat Notre Dame and Clemson/Ohio State. The problem is the SEC was really down this year. The "second best" team in the SEC was Texas A&M who beat a bunch of bad teams by low margins, isn't ranked as a top 10 team by most analytic models, and generally looked very uninspiring for most of the season. The third best team in the SEC, Florida doesn't play any defense. The fourth best team in the SEC, Georgia didn't have a passing game until late November when JT Daniels was finally healthy enough to play. By then, it was too little too late. LSU was awful. It was just a bad league this year which is why 2020 Bama's SRS is as low as it is. They have to beat Notre Dame and Clemson convincingly for them to even get in the conversation. I personally don't think they're as good as the championship teams from 2009-2012 or were as good in the regular season as the teams from 2016 or 2018 who obliterated better opponents.