The original XBox is emulated brilliantly for some games. Apart from one bug and the control differences, I'd find it hard to tell which was HALO 2 or 3 from a short bit of gameplay (short enough for me not to notice differences in textures, plot etc.). The problem was, each game had its own profile for the emulator, as no two games required identical settings, and I assume some static recompilation had to be done as well. They could have it perfect for every game, except it would require to much work to be worth it: some people would buy a 360 because it could still play HALO 1 and 2, but there would be obscure games no one cared about.
OS: Windows 10 64 bit Professional
CPU: AMD Ryzen 5900X
RAM: 48GB
GPU: Radeon 7800 XT
CPU: AMD Ryzen 5900X
RAM: 48GB
GPU: Radeon 7800 XT