Shenmue graphics were made to simulate the real world and all games will be stylized in some way or another
You've really lost the plot now! Just kidding, that would be a ROJM response. But I'm sorry, if you can't see that every single texture in Shenmue is a painting, and that the game's art direction is to resemble a painting, then I can't help you any further. You want Shenmue III to look like Battlefield or something, just for bragging rights? Forget it. I suppose you think Valkyria Chronicles would look better in Unreal Engine?
As for the textures, I'm not saying that every texture, or even most textures are high resolution. But some of them really are. It's not a result of upscaling, either. Their native resolution is just high, comparable to (and sometimes better than) the small details you'll see up close in something like GTA. Mostly decorative items, like items in shops, posters on walls, etc. -- small details, but it's the details that help make the world come alive. In any case, the original point is that some of the work, not all of it or most of it, is already of acceptable high quality, and that's a testament to how forward-thinking Suzuki and co. were in the time of developing Shenmue.