No offense to the OP, but the 2021 Bengals are nothing like the 2001 Patriots. And this Super Bowl is nothing like the Pats/Rams Super Bowl.
The 2001 Patriots were a great defense with an efficient, but unremarkable offense. The 2021 Bengals are a great offense with a mediocre defense.
The 2001 Patriots had the best defense in the league in the second half of the season and only lost to the Rams in the second half of the season. The 2021 Bengals did not have the best second half offense or defense. And they went 3-3 down the stretch (although they rested their starters in the last game).
The Pats went up against a greatest of all time offense. The Rams have a great defense, but not a top defense of all time and they are far more balanced. And the 2001 Rams were clearly the best team in the league during the regular season and #2 wasn't even that close. The 2021 Rams didn't even have the #1 seed and struggled at times this season.
The Bengals could win. But being the underdog who win with a second year QB may be where the similarities end.