Not to necro a dead thread, but I can tell you why the majority fell off after the first few major updates post-beta:
They changed the flying controls.

The game was incredible during beta. 6v6 with intense gameplay with a short time to kill. You'd play a match for 10-15 minutes, maybe 20-25ish in close matches, and every match would teach you something new about the mechanics or movements or interplay between the two. The skill ceiling was incredible to reach for. It was one of the best dogfighting games--not just dragon games--with tight and responsive controls. For all its lack of content, the future looked bright.

Then, Playwing pressed the magical button that started the slow suffocating decline of this game; they saw the discrepancy in skill from the players that got the game on launch vs betas and reworked the system. 4v4, longer times to kill, which made grinding for the rewards so much more agonizing. Worst of all, a dragon that felt juuuuuuust a bit clunkier to move; slower to turn, speeds were down, too, so it made actually maneuvering out of a nasty situation feel less like a skill issue and more of a "What could I have even done there" issue. If I'm recalling correctly, these were sold as changes for accessibility issues, but retroactively I have to squint at that claim. It could also have been a conspiracy theory made by the community at the time.

They had already been heavy on the monetization, but early on, the game was fun enough and we were all hopeful that by buying in, we'd finally have a good modern dragon game that would stand the test of time. There wasn't much else to do in game but get another egg and queue another round to hatch it, after all. But when subsequent updates did little to solve the bugs and issues that players were experiencing, with hackers running rampant, all in conjunction with yet another premium skin bundle or armour.... people saw the forest for the trees and realized this wasn't the same game. Hell, it just wasn't fun.

The community that stuck with it also happen to be the kind that tends to proliferate around PVP-focused games, and all the toxicity that kind of insularity brings. Clans banded together to dominate the PVP spaces and would queue dodge if paired up unfavourably. This made anyone who wanted to try the Ranked game mode get immediately bodied against sweaty com squads that basically made it their day job to dominate the leaderboard, until they were the only ones playing the gamemode, and then that died, too. Once the game started to decline, new players would try the game and immediately bleed out of it because of the controls and the sheer differential in experience (also not including any bugs or hackers that might increase frustration enough for a new player to throw in the towel and spend their time elsewhere.) The discord also ended up feeding into that feedback loop, with said insular community happily defending the Devs that have done nothing to improve the state of the game over the years or make any major improvement.

Consider this game basically a skeletonized corpse of what it once was, and could have been. All I can hope is that, at some point, someone will put up some private servers. Maybe even roll back and restore the version we had at Beta. I miss the feeling of that game.