Well, that might not be available with todays technology, but who knows what might be capable in 3-4 years. The new Tegra Xavier T194 is capable of pushing out 1.4 TFLOPS at FP32 (compared to Switch 384 GFLOPS in FP32 and the X1 chips full clock at 512 GFLOPS). That's almost a 3 times performance increase in four years. Give it another four years and we could potentially have another 3 times performance increase at ~4 TFLOPS.
Of course TFLOPS don't mean everything, but with the fact that new architectures come easier programming capabilities it is possible that the next Switch could rival the PS4 Pro in terms of raw power. Besides, a 3-4 times increase in power isn't a generational leap. That would only be slightly larger than the jump from Gamecube to Wii, which was around a 2 times increase in terms of power.
Power consumption and manufacturing node are factors here, though.
The Tegra X1 consumed 10 - 15 watts to deliver 500 - 600 GFLOPS and even then it had to be underclocked to fit on the Switch. The figure you're quoting probably refers to the 30W TDP option. The Xavier chip under similar power constraints is a 600 - 800 GFLOPS chip. Even when you factor in the IPC gains of the Volta microarchitecture, it's unlikely the average improvement for games would reach a 2 times increase.
Now, we do more or less know how the next three or so upcoming nodes will perform in terms of feature size and power consumption. How close to a PS4 Pro a ~3 nm or so Switch 2 would perform, though, remains to be seen considering we know nothing about future architectural improvements or which clocks or die size Nintendo would use to fit their power and cost constraints.
But to assume it could match it certainly risks falling into the same optimistic trap a few members here fell into some four years ago, when they were sure the Tegra X1 could deliver a portable console at least matching the Xbox One. And we know how that one turned out.