2 main reasons I think relegation is a good thing is that, firstly, you cannot start a season badly and just sit and wait for the next one, doing this could literally kill the club. Secondly it can be a blessing in disguise, my rugby league team Hull Kingston Rovers got promoted in 2006 and battling relegation every year, barely surviving year in year out. We spent about a decade like this, fanbase dwindling, before heartbreakingly getting relegated I'm the last second of the game in 2017, the contrast of losing every game in the top flight to winning most games (albeit in the second tier) really helped grow our fanbase and send the club in an upwards trajectory. Fast forward to 2025 (last year now), we won everything we possibly could.