Few esports leagues keep the same structure for more than a couple of seasons. The churn reflects the number of incompatible things a format has to satisfy at once.
A league is a broadcast product before anything else
Revenue depends on people watching, and viewership depends on matches that are scheduled predictably, matter individually and finish inside a slot an audience will commit to.
Pure competitive structures rarely deliver that. A long round robin produces fair standings and also produces meaningless late matches between teams with nothing left to play for.
Formats therefore get reshaped towards elimination, tiebreak stakes and shortened series, all of which sacrifice some accuracy in ranking to keep the calendar watchable.
Fairness and drama pull in opposite directions
The fairest way to identify the strongest team is many matches under identical conditions, because a single series is a small sample of a noisy contest.
Audiences, however, respond to jeopardy, and a system where an upset cannot matter removes the reason to watch anything but the final weekend.
Every format is a position between those poles, and every position generates complaints from one side, which is a standing pressure to change it again.
The developer controls the game itself
Traditional sports have stable rules. An esport does not, because the publisher can change balance, add characters or alter maps between seasons.
A format tuned to one version of the game can become unbalanced when the game shifts, particularly if a change makes certain strategies dominant in short series.
The league is downstream of a product roadmap it does not control, so structural adjustments follow major game changes as a matter of course.
Regional pipelines have to feed the top tier
A league needs new teams and new players, which means lower divisions, qualifiers and academy systems that connect to the main competition somehow.
Those connections are where formats break. Promotion routes that are too open destabilise the commercial side, and routes that are too closed starve the talent pipeline.
Leagues oscillate between the two, tightening access after instability and loosening it once the competitive standard visibly stagnates.
Franchising changed the incentives
Where teams buy permanent slots, relegation disappears, which protects investment but removes the consequence that keeps weaker teams competing seriously.
Organisers then have to manufacture stakes through playoff structures, points systems and international qualification, all of which are levers that get adjusted annually.
The result is a format that changes not because the previous one failed outright, but because the balance of commercial and competitive pressure moved again.