NIS has many games published with target a specific niche Japanese audience. They don't develop everything with West in mind. Disgaea must be the only franchise that does some respectable numbers worldwide and even that saw a decline at every region with 5. If it wasn't the late Switch port to recover lost western sales there would be a big drop comparing to 3 and 4.
and because of the switch version, the platforms you're going to see from nis and nisa are ps4, switch and pc/steam.