Earlier games were written to the bare metal, so copying the hardware was the hard part. More recent stuff is written to APIs, so you can avoid most of that, but the addition of 3D and more complexity means itβs just difficult in a different way.
...and there would also have to be another huge jump in (mainly single-threaded) computing power to make emulation at native speeds possible in a browser. Those consoles have relatively powerful GPUs and CPUs.
GPU pass through makes a huge difference in running games in a VM. AFAIK current gen consoles are mostly PCs-in-a-box, I am hopeful for the future of emulating them.
