I think the main thing going for Dragalia over it's competition is the fact that standards for first-parties seem to be lower than for third-parties. XC2 and ARMS did pretty well, but they're nowhere near the massive breakout of Persona 5 or the legacy of SNK's works. Who knows why, exactly, the standards are lower. Maybe it's because Nintendo can promote them later on, or maybe it's the cross-pollination of playerbases, or perhaps it's just because there aren't any legal issues to sort out. Whatever the reason, I think Dragalia's not 100% written off because of the different standards it's held to.