Maintenance was a major issue for people who weren't in the top three. More importantly though, maintenance costs for Legendary were so high that it wasn't worth it to play Legendary for 2/3 of the players there, and as a result, no one did play.
While maintenance was a thing, I'm pretty sure that fewer than fifty Legendary matches occurred (over what? six months? a year?). The costs were so prohibitive that most of these matches were exclusively done by streamers and players who were overflowing with surplus credits after having unlocked all of the T5 ships. They were essentially exhibition matches. Once maintenance was replaced with battle bonus, people started actually playing Legendary.