So I showed you a lot of examples and you still don't believe that tanking is too popular.
The salary floor helped a bit but it's way too low to make 1st and 2nd league tanking unefficient. Salary floor in division 3 ist ~90k/week. Average income attendence: 190k, TV-money: 90k, merch: 27k. Average expenses: 270k for players, personnel: 43k, Scout: 7k
That leaves tanking teams in league 3 weekly earnings of (numbers of the tanking team in my league):
164k attendence + 27k merch
personnel: 30k, Scout 20k
--> 141k earnings per week. And don't forget about training: you don't have to make compromises in training because you don't care about winning.
And I left out the Cup. Most tanking teams do all they can to stay in the Cup rather long. In Germany you can be lucky to get 5-6 Bots in the first 6 rounds. More money easily gathered for tanking teams.
The easiest fix would be to stop people attending games if a team lost e.g. three games in a row with more than 50 points. There are other criteria how to indentify obvious tanking. It's really easy to distinguish between tanking and forgetting to set a lineup for one game.