Square and Enix support were pretty strong for Nintendo early on, but it seemed to me like they largely abandoned Nintendo starting with N64. Square dropped Nintendo for FF starting with FF7, while Enix dropped Nintendo for DQ 7 and DQ 8, returning to Nintendo on DQ9. Square only gave Nintendo some of the KH spinoffs and none of the main series games so far. Nintendo does get some Square support still, with Bravely Default 2 incoming for instance, but Capcom seems to be supporting Switch even stronger, they already released several games on Switch, with some MH exclusives inbound for Switch. Seems to me like Capcom Nintendo support has been more consistent across all generations.
Square support for Nintendo platforms only saw a real decline for the home consoles, and of those only N64, Gamecube and Wii U to an extent.
As far as I know, the handhelds received great support and were somewhat pretty consistent over the decades, with games like DQ, FF(mostly spin offs), one time franchises like The World Ends With You(though a sequel is now comming) and so much more.
I do think Capcom has a real shot at being first here, but Square presence on Nintendo systems is as strong, in my view.
My (locked) thread about how difficulty should be a decision for the developers, not the gamers.