I think Switch 2 may actually have 5nm available if we're talking 2023.
Apple is moving to 5nm this fall for their iPhones, in three years time for mobile chips 5nm will be a common and well worn in.
Maybe we see a version of the current Switch (and Lite) move to 7nm around fall 2021 in another refresh for example, 5nm for Switch 2, then the Switch 2 Lite could work at 2nm/3nm say 2 years later.
Yea 5nm would be even more crazy and because of the low power requirements and how efficient Nvidia GPUs are with power consumption, they could put a more powerful GPU in there instead of only 256 cores. Also it is rumoured that with next gen, Nvidia will have RTX in their entire line up of GPUs. Again, we will see how true that is but if it is true, I can see the switch 2 having Tensor cores for sure.
PC Specs: CPU: 7800X3D || GPU: Strix 4090 || RAM: 32GB DDR5 6000 || Main SSD: WD 2TB SN850