I feel like Nintendo keeps making games that push their current hardware too far and the Switch is the worst they have been with that.
The ds eventually moved to 3ds, and then eventually got a new 3ds for more power. For the case of the Switch, it seems they aren't interested in releasing a version more powerful to run the games they insist on making. As for a new system entirely, it would be unknown if backwards compatibility with Switch games will be a thing or not. People hope it will. Personally I think for the digital age we are in, purchased games need to be tied to the Nintendo account instead of the console.
Honestly I could see Nintendo moving away from consoles, and make hardware accessories instead for Android and or PC. I find it hard to believe that they would continue down the same road and continue with high prices.