Im not a big fan of these very long lifecycles, fatigue sets in for me after about 5-6 years and I am ready for upgraded hardware. However, I do believe longer life cycles are here to stay. Generational leaps are getting harder and harder for console makers to attain within the restrictions of a mass market price point. Technology was advancing so rapidly that for years it was possible to turn out a new console every 5-6 years that provided a generational leap and still hit the target price point. Take the Xbox to Xbox 360 transition, that was only a four year generation but Microsoft was able to go from a 20 Gflop console in 2001 to a 240 Gflop console, a 12x upgrade in only four years and that is still underselling the upgrade because programable shaders revolutionized graphics rendering at that time. Now compare that to the 5-6x upgrade for the PS4 to PS5 that took seven years and didn't bring along any revolutionary changes to rendering technology. If the PS5 were capable of making better use of Ray Tracing, then perhaps that would have been a revolutionary change in rendering technology, but because it is rather limited with most games sticking to more traditionally rendering techniques, its a more straightforward leap from the PS4 to PS5.
Because the road map for smaller and smaller nodes is rapidly slowing down, we know that we cannot expect to see significant performance improvements from smaller nodes in the future. Unless some completely new chip technology comes along and revolutionizes that industry and currently that doesn't appear to be happening any time real soon. Assuming T239 does end up being a 3Tflop SOC, it will be increasingly difficult to create an SOC that offers a 10x upgrade a handful of years later that still fits within the limitations of a hybrid console. Outside of a disaster with SNG where Nintendo is forced to hurry new hardware to market, I entirely expect Nintendo to enter this upcoming generation with the expectation of a 7-8 year life cycle.
I got my NES back in 1989, SNES in 1995, and N64 in 1997. In a shorter amount of time than Switch has been on the market, I went through three console generations. Its true that I got my NES and certainly the SNES a bit later in their life cycle, but even if you look at it from the perspective of release dates, the NES released in the US in 1986 and the N64 released in 1996. That's three consoles released in matter of a decade, and all of them provided significant upgrades. For those of us who are old enough, we were very fortunate live through the rapid advancements in gaming technology. Things are at a snails pace these days by comparison.