The current Switch is 0.4tflops when docked. The new chip leaked for the next Switch can easily do 2.5-3tflops (depending on clocks) when docked then they'll have DLSS to deploy which will enable PS5/Series "impossible ports" by running them at native 480p then using DLSS to take the image quality up to 1080p.
The next Switch will be a ginormous leap over the current Switch in compute power maybe even bigger than 3DS was to Switch in handheld mode. In the region of an old school 10x generational leap. I expect Nintendo's first parties to target 1080p native in docked mode then use DLSS to get up to 4k. If they so desire they will output visuals on par with Ratchet PS5 with this hardware if they are willing to spend much more than they currently do on development.
This will be their first huge leap in development budgets since the HD Wii U era but I'm not convinced they have any need to target beyond Switch in terms of geometric complexity, shading and models. As shown above games like BotW and Mario Odyssey already look phenomenal in 4k and that's games developed around 3GB of pathetically slow RAM, a 0.2tflop GPU and a mobile phone CPU from a decade ago. They will truly shock people if they push this new hardware. It's good that Nintendo will finally be in the ballpark of cutting edge visuals again. It only took them almost 20 years...