Actually there are a lot of upscale models for pretty much every kind of art, you just have to find them 
So I think the realistic graphics shouldn't be an issue. But making a texture pack is still a lot of work and pretty time consuming. So people make them just for their favourite games.
So I think the realistic graphics shouldn't be an issue. But making a texture pack is still a lot of work and pretty time consuming. So people make them just for their favourite games.
Status of my GC texture packs:
Harvest Moon: A Wonderful Life v1.1 (updated: 17.04.22)
Need for Speed: Most Wanted v1.3 (updated: 10.07.22)
Need for Speed: Underground 2 v1.4 (updated: 10.07.22)
Harvest Moon: A Wonderful Life v1.1 (updated: 17.04.22)
Need for Speed: Most Wanted v1.3 (updated: 10.07.22)
Need for Speed: Underground 2 v1.4 (updated: 10.07.22)