Up to the Switch, I absolutely agree but now Nintendo seems to have turned it all around and actually seem to be in an innovation overdrive. Series like Mario Party and Mario Tennis have been changed gameplay wise after stagnating for so long. They keep expanding their IPs now and are being aggressive with building new IPs like with Daemon X Machina and Astral Chain. The recent delays in MP4 and AC:NH also give indication that they're really taking the quality of their games seriously. They know they've sat on their laurels for too long and now they're scrambling to fix that.
They've been doing an okay job so far but in all this, the one thing that stands out is Pokemon and that's because Nintendo has no direct control over it. I see Pokemon's stagnation more in the hands of Game Freak than Nintendo. Both may want money but they clearly at direct competition with what they want to do now.
Game Freak have clearly been looking to find new pastures while Nintendo, and TCPi by extension, have all the indication they want the show to go on. Mobile or not, at this point, I have to wonder why hasn't Game Freak spun off a studio to focus solely on Pokemon and leave Game Freak to do what it wants. They still want the Pokemon money too since it's stable but they haven't tried doing this despite being an obvious move.
What's especially baffling is that they have a subsidiary developer already, Koa Games, and they have been helping develop Pokemon games for mobile. Why not move all Pokemon production to them as well as placing dedicated staff with them as well and have Koa Games be the new label for all Pokemon game products main-line, spin-offs, and mobile?