For example PS2 require specific "care" for many games that uses how the hardware is for graphical stuff but PS3 require beyond care but "love" for many games using the way how PS3's CPU work. Naturally it's not how PCs work therefore adjusting it is too much work.
However emulators are not working magically, there is a limit of what you can do and that limit is hardware. That's why PS3 emulators would require specific PC hardware to work decently. There is no such thing as "writing a super emulator that would allow you to make PS3 games work on NES!!!" lol.
In detail due to way PS3's CPU works and how a PC has to process this via emulator you need a CPU that has very high single-core processing power and very high IPC. After that high core and thread amount is cherry on top on being helpful. PS3 using lots of threads and therefore there is more in need for cores and threads so I would rather consider some 8 cores 20 threads CPUs but naturally core and thread amount is not enough if the CPU is not fast enough. Also the CPU better support AVX-512. Why?: Simply put the way PS3's CPU work similarly works as what AVX (Advanced Vector Extensions) does that is closest you can get on a PC hardware. "512" means the CPU can process that "wider data" at once which benefits PS3 emulation for faster processing.
As for GPU of course speed is obvious need but it gotta have a decent vulkan support and high VRAM like around and above 8 GB.
As for RAM, besides speed better consider 16-32 GB RAM. And better make the both emulator and game present in a decent SSD.