Your assumption is that they developed the PS4 emulator 13 straight hardcore. There are systems that are harder to emulate, just because it is more demanding and much more complex like PS3. It needed loots of time and efforts to be on this level of RPCS3 emulating PS3. On the other hand, the developers of shadPS4 made progress very quick once they started fully developing the project. And you don't even have to have a huge PC, because lots of the x86 instructions can be reused on your PC without emulating the whole thing. That's what it means its the same architecture, it requires less resources to run than emulating it in full.
Before getting sarcastic, you should inform yourself about topics you are arguing.
shadPS4 Initial release September 29, 2023; 2 years ago.