In theory you can recompile by translating the instructions, the problem is the game engine assumes things about the hardware that is no longer true when running on your computer, such as memory model and more. Patching this up makes it slow.

give it a couple decades of manpower and eventually it will become viable

Well, someone did exactly that with Sonic Unleashed (XBox 360) IIRC. And a few select N64 titles.

The produced code is complete garbage, it's basically the machine code disassembled, but instead of assembly it's some technically valid C that can be forcefully shoved back up a compiler. Due to register sizes and calling conventions being different across architectures, there was zero chance of making the giant blob cooperate with native builds of the libraries it used, so some poor people had to pick out everything machine specific in the giant pile of shit that came out of the disassembler and fake it. That took forever.