I've crunched the numbers and I am fairly confident that the Switch 2 GPU, on a raw power relative comparison with consoles, at full power is about as powerful as 80% of a PS4 Pro, so likely less in handheld mode. How much less in handheld mode, it's impossible to say without knowing the power profiles. So it's 4/5th as powerful as a Playstation that was released in 2016, about a year before the Switch 1 debuted.
Compared to the Tegra X1 GPU, in terms of raw computational power, that would make the Switch 2 GPU approximately 6.6 times more powerful.
Interestingly the top line Playstation, the Playstation 5 Pro, is actually more powerful relative to the Switch 2, than the PS4 Pro was to the Switch 1. The PS4 Pro was only ~8.2 times more powerful than the Switch 1, whereas the PS5 Pro is 10.7 times more powerful than the Switch 2. So I guess another way of comparing the power of the Switch 2 is that it is ~9.35% of a PS5 Pro.
I point out I am neither pro or anti-Switch 2, this is a pure maths comparison in terms of raw computational power.