if any advantage in tanking, I find so boring both playing to loose ( a real mess of time, as I do not have so much to prepare and follow the season)
and repeating same level in the next season.
if i do not care about season, I use it to have a functional team for next season,with the lowest expense and regardless from quality and final results.
If you get promoted,it means you chose a good strategy to valorize your players,for sure better than your opponents.
Why destroying if you managed building with no great expenses?
it's not sure that tanking will return you a team that will easily adapt to new season....
I failed (not tanking) level 29 about 17 seasons ago: it took me lots of seasons to be competitive again...
During that period I had everything but continuity in my team with long cycles of debacles when my team left me
alone (they simply did not play at all as if they were in a strike).
Never any good news from failures for me....