Maybe never with current technology? Looking just at the CPU and assuming you need comfortable IPC overhead for emulation, the 386 was from early in the Dennard scaling era and modern CPUs are 1000x or more faster single-thread. Since maybe 2012 that hasn't moved anywhere near that, certainly less than 10x.

Figure 6 in "A New Golden Age for Computer Architecture" is a good representation of that effect: https://dl.acm.org/doi/epdf/10.1145/3282307.

For the GPU things are potentially looking better! But since distributed shaders/kernels are higher-level compiled for your specific device, there's less of a need for emulation.

Either "already" or "not any time soon", depending on how you count.

Already - because you have VMs and backwards compatibility. As long as you keep using Intel x86_64, your apps would run, no emulation needed. Or you can use the VM.

Not any time soon - because the computers are not speeding up that fast. 10 year old computers are still being used today, and even the latest CPUs are not orders of magnitude faster. So for a full-system emulation, the most well-known ones is x86 VM's on Apple Silicon, and according to reports, full-system mode is still not close to regular PCs.

>Holy cow, a 386 with VGA and SoundBlaster on a $1 MCU?

The right software -- really does add value(!) to (let's-just-say-it-isn't-an-nVidia-GB300!) hardware, now doesn't it? :-)

I don't know about anyone else -- but I'm sold!

The value proposition on this one is truly awesome!