Nintendo has a history of poor transition strategies. Their burn it down and restart from scratch strategy means that every single generation is an entirely new game.
So, it's partially up to Nintendo, if they stick to this old-fashioned broken transition system, or if they update it to something proven to work like the Apple/Samsung model which doesn't burn down the previous generation, but builds onto it and develops their ecosystem into bigger and better things. It would be great if Nintendo released a new generation of Switch and had low-end compatibility with the previous Switch on most of their software -- it's conceivable that some of their newer software would depend on features exclusive to updated hardware, but that's going to be a small set of games.
Mostly, older games shouldn't require new ports for the new hardware. The Switch 2 should allow for easy updates that can upgrade Switch 1 game performance. I'm not saying that some new remaster release can't happen; only that older games should be able to be easily updated to take advantage of the more powerful hardware in what way they can: higher frame-rate, effects, and loading. This shouldn't be too difficult on the Switch hardware, since devs routinely do this on similar hardware.
If they burn Switch down and make some new platform from scratch again, then it might be successful, but it might completely bomb.
If they make a Switch 2, an evolution of the Switch, it will be successful since the Devs and market place is reasonably predictable. There is nothing like Smartphones around that could make the foundation brittle. 3DS might have been MUCH more successful, even in light of the rise of smartphones, had a few things happened: A) They launched at a more reasonable price for a handheld, B) No insane anti-3D sentiment, and C) an actual 3D film service like netflix. Something like D) More stable 3D at launch, probably would have helped a lot too. I doubt Switch is going to fall into the same pitfalls as the Wii U and 3DS - I think part of their issue is they added in components that were too expensive, and that jacked the price of the products up too high for consumers.
But anyway, I have a strong feeling Nintendo is not going to fuck Switch 2 up. It will be Switch 2 and not Switch U.
Switch U would be a failure =P
It's a Switch that can transform into a VR helmet, but there are a couple of catches: it has to be docked, so you can't move with it on, Switch U will cost 550 USD, and you can only have 1 VR helmet per multiplayer game, so you'll have to play asymmetrically =P
I describe myself as a little dose of toxic masculinity.