It was just a two question + your name form: type-in your #1 pick but also why. Full-on first past the post, single vote only, no option to name other games. Pretty flawed methodology overall.
That said, I will admit that I did put in Shenmue and while I didn't expect it to get #1, I hoped it'd be top 3 at the very least. I really do trace more or less every successful strongly story based open world game of the 2000s back to a combination of Shenmue and Half-Life. Shenmue's story didn't have a super wide appeal and would be completely uninteresting to most teenagers at the time (which was still the main gaming audience), but the method of storytelling is top-notch, and its open world just felt far more genuine than anything predating it. Meanwhile, Half-Life did an excellent job at telling a story that looks boring but is actually very interesting, and did so in an engaging, if not particularly open world way.
We won't know for sure what's actually going on under the hood until the console is cracked wide open or there's a devkit leak, but my speculative guess is that some details of the GPU are 'emulated'/recompiled. PC AAA games tend to include lengthy shader pre-compilation wait times, console games don't have that wait time because the shaders are pre-compiled by the developers when building the game, specifically for one piece of hardware. The games themselves then fully rely on those pre-compiled shaders. They're going to need shaders that work with the Switch 2's GPU, which is going to involve some kind of imperfect translation process.
AMD was able to design better hardware that works with older compiled shaders, as done in the PS5/Xbox Series (and Pro consoles). That's not a super common feature, but I imagine that AMD is more motivated to keep Microsoft/Sony happy than Nvidia is to keep Nintendo happy. AMD's graphics division might as well shut their doors if it wasn't for the consoles, meanwhile Nvidia is raking in trillions from the AI boom and would rather forget about gaming.