Wouldn't it be better to work as Duckstation? Or is PCSX-ReARMed the same thing?
In theory it's better to start completely from scratch using the decades of console and emulation knowledge gained, which is what duckstation is. In practice it's a lot easier to improve and refine what already existed before, which is what PCSX rearmed is to PCSX-r, which is a refined version of PCSX and by extension Wiistation to WiiSX, which is originally also a port of PCSX-r.
Wiistation and WiiSX run enough PSX games full speed that there doesn't really seem to be any particular reason to start over from scratch. Really the only thing I'd say is missing is hardware rendering and a couple of more peripherals support like the mouse and the negcon