I think releasing a spin-off like FEW this early in the Switch's life before even having a main series title on said system was a bad idea. Most of the fire emblem fanbase is firmly on the 3DS (and FEW 3DS is unappealing when standing next to the Switch version).
Fire Emblem fatigue is probably also a thing. I'm really, really curious how the Switch's proper Fire Emblem game will do...
Is Fire Emblem fatigue really a thing? I've seen it mentioned a lot, but I don't see where it comes from.
Over the last year or so, we got FE Fates, FE Echoes Shadow of Valentia, FE Warriors and FE Heroes. Fates and Heroes were massive successes, and I would say that Shadow of Valentia did well too, considering it's not a mainline title but 'just' a remake of a not very popular title. FE Warriors didn't do well, below the Zelda Warriors game, but FE is not as popular as Zelda in Japan, the lineup was geared towards the newcomers to the series while I would think a musou should appeal to the core fanbase, and in general there is a fatigue for musou games. I don't see the FE fatigue manifested in this.