It was mainly due to them embracing rollback net code and being part of EVOs line up during covid. Problem is that the big fighters revised their netcode since then and it's been relegated.
Nah, even out of the gate, it's done far better than the likes of Punch Planet, for instance. They just made a good game, and people paid attention; perhaps not as much attention as they wanted or needed. If you ask me, they appeared to have started overscoping once they got their initial success. The Salt Mines mode seemed like a big money sink that had a detrimental effect on the matchmaking, for one.
I mean, the game is good, but you can see the spike in steam charts right at the point it was announced for EVO. Like outside the initial release, the game averaged under 20 players. After that they spiked and then just slowly got back to averaging less than 20 players the last few months.
I like the game, but it's not comparable to the other successful indie titles like UNIST or Skull Girls. Yeah it kills punch planet, but outside the first few months it released to may 2021, it did similar numbers.
UNI and SG are themselves far more successful than most games. So yes, not as successful as those two, but still more successful than most. Evo is also a kingmaker, and you can see spikes in all of the announced Evo games when they're announced and present at Evo.