Is it not that the SNES mini's hardware is a bit more powerful than the one of the PSX? Thus making sense buying that one for hacking and running emulation, although I think the PSX controllers are way better.
This made me think: https://www.youtube.com/watch?v=ol12g5GxI7Y
But apparently RetroArch runs perfectly on the Playstation too, plus the emulator of RetroArch runs PSX games a lot better than their built in one, strange enough.