How about an even longer tournament?
It turns out that Swiss tournaments use the formula (P + 7)/5 to set the number of rounds, where P is the number of players.
EDIT: Turns out this formula may be incorrect. We’ve found examples that contradict it and a working hypothesis is that the number of rounds is capped at 8.
Thus, a tournament with 500 players is set for over 100 rounds (however, I’m not sure that is reduced if some people drop out). With over 2000 players, that would be over 400 rounds.
Of course, a Swiss tournament would also be different in giving only one game to each player per round, but it’s all about going the distance here.