I feel like we're also hitting that general malaise as a system reaches end-of-life, regardless if Nintendo has a successor announced. We're finishing Year 6. This is just like Wii circa 2010-2012, where there's a few good games but I'm looking at other options (then Steam, now Steam Deck).
Also, I think Nintendo is probably holding things back for a Switch 2 launch in 2024, namely Mario Kart 9 and a mainline Mario.