Not the platform, the company.
Used to be that Nintendo was diversified enough to be able to take a bad year or even gen in one of their businesses (like if the Gamecube flops, they still have healthy GBA sales, for the Wii U they had the 3DS to keep them going and vice versa), but now all the eggs are essentially in one basket (the same decision Sony made when they stopped pushing the Vita to focus on the PS4/5). If any Switch device fails for whatever reason, then they are kind of out of options in the market except to try and build up marketshare again in the high-power console segment or look to PC (does not mean posting games on Steam).
The reason they're doing films and theme parks is because they need to create new consumer relationships with new kids as the current ones age out of Nintendo (or gaming altogether). They have also benefitted greatly from the rise of the Nintendo Adult (same idea as a Disney Adult).
The beginning of delusion lies in the assumption that change will never happen.
I see the kids in my family, Mario games are a distraction from Roblox and Fortnite. Even Donkey Kong Bananza, as amazing as it is, has not been sufficient for them to drop Roblox while they finish it.