It seems for some reason Nintendo's in house games' HDR support seems to be more for increasing accuracy of colours and shapes rather than increasing brightness. Running on my QD OLED monitor, Breath of the Wild's Switch 2 upgrade does not look super bright with massive contrast (as most PC HDR would be), but you have things like the sun going from a white blob (on an SDR Switch 1 as well as an emulator) to being much more detailed due to the increased gamma value range. On Welcome Tour as well, the fireworks demo definitely shows much more detail in the explosions, but does not use the peak brightness of the monitor. Similarly, Switch 1 games look a bit more muted with the Switch 2's HDR output (compared to the tone mapping the monitor uses for the Switch 1's SDR output), but with colours closer to the printed box art and other sources. I think we might see future Nintendo published Switch 2 focused games try and use the HDR for a higher brightness output, or we might see the more accuracy same brightness trend continue. This is likely a development choice, and explains why Cyberpunk 2077 (a game with existing HDR on other platforms, where the tendency is for higher brightness with more "pop" with high contrast) looks quite different in HDR on Switch 2 compared to the Nintendo titles.

The integrated display is definitely not the best thing in the world, but it does what it needs to do pretty well. High refresh rate 1080p with some light HDR looks perfectly fine to me, and it definitely looks far better than Switch 1. It's very good for my usage. The brightness could have been higher though, considering this is a portable device that you might want to use in bright sunlight on the train or something (high end phone screens get 1000+ nit brightnesses for this reason, and as far as I know Deck OLED does at least 800 or 900).

You all need to remember the target audience of these consoles - Nintendo streamers and children. These people do not care about HDR as much as your traditional PC gamers do. They are going to cut corners to make the console as cheap as possible and only as powerful as needed for their gimmicks to run smoothly.

I dislike the Switch 2 and Nintendo for many reasons, but the lack of good HDR is not one of them.

Edit: realizing after the post this is a Nintendo group, so I am prepared for my downvotes.

I feel like people always miss the point of a Nintendo console. While it’d be cool to have HDR and OLED and such, it’s not really a big deal. It doesn’t really impact my ability to have fun with Mario Kart or Party. It doesn’t change my enjoyment of animal crossing, etc.

I’ve got a PS5 hooked to a 4k HDR 120hz screen, and enjoy the performance and graphical fidelity regularly, and there are some games I’m still picking a switch up to play. Heck, I still play on a Wii fairly frequently. The controllers, game types/styles, game quality, accessibility, replayability, etc.

Well it's a Nintendo console, so that's right about where it's expected to be.