Software engineers over at Google have hacked the PlayStation Portal to run the PSP emulator PPSSPP and demonstrated their accomplishment by showing it running GTA for the PSP.
Officially the Portal can’t run any games without being tethered to a PlayStation 5 but this proves that the device is technically capable of running emulators as modern as the PSP.
So if the engineers release the method for this which is entirely software based and doesn’t require any physical tampering which they say they don’t plan on doing in the near future, or someone else figures it out there’s no reason it can’t play PS1 games too and a whole library of Sega and Nintendo games for the SNES and Mega Drive, among others.
It would still be an expensive device to buy as a retro emulation machine, especially when the Vita exists and can already play a whole host of retro games and they can bought for around £90.
Similar story with the PSVR. You can use it with a computer but you don’t get Sony’s proprietary 3D sound.
This might have changed in the past couple years but I think you still need a secondary headset. You can’t just use the headset’s aux port.