Last Team to Tank a Season and Win a Super Bowl a year or two after?

The eagles sucked during Jalen Hurts first season(2020) and went 4-11-1. They won 23 games the next two seasons and nearly won a SB against the chiefs.

The bengals didn’t win but got damn close against the rams in 2022. They sucked during burrows rookie year(granted he got hurt) and were awful before.

2018 49ers were 4-12 and went 13-3 in 2019 and were dominant until Shanahan forgot to run the ball up 10 in the SB against the chiefs.

The Texans won a playoff game last year after being dismal for a while. They look like SB contenders this year.

Not quite what you asked but there’s many examples of a Super Bowl contender being born right after dismal seasons just in the past 5-6 years.