There's definitely a business sense to bringing out a Switch 2 sooner rather than later. Especially with the scalability of software development and the fact that all companies actually strive to maintain profit and revenue at their highest levels, as opposed to experience years of continual decline. People mistake what has come before in terms of console cycles as some fixed intentional design versus a product of many technical limitations relating to hardware progress and the ability to support hardware with relevant software.
Now this I could see, the Switch itself surviving well past its successors introduction. They could treat Switch/Lite like the cheap older brother to the new shiny device (which we call Switch 2 for lack of an actual name) and keep pumping them out along with studios wanting to make cheaper budget games that come out ob both Switch 1 and Switch 2, while the heavy hitters come out with modern engines on the Switch 2 exclusively.