retroreddy
Gamecube runs very slow (see videos of ETA Prime, where he tested dolphin on RPI4)
Wii, PS2 and PS3 will never be playable (or even work) on RPI4.
In my eyes, RPI4 is not that much faster than RPI3 (overclocked).
See the compatability list, which systems are playable on RPI4
https://batocera.org/compatibility
For the price of RPI4 i would rather buy an old/used mini pc like older Intel NUCs for example (even oldest Intel NUC with Celeron is more powerful than RPI4) or used Mini-ITX PC with Haswell Celeron/Pentium or i3.
