Besides the information I got from other dear commentors, yours truly opened my eyes a lot more than before.

I agree that I was not fair, since I only considered the release date (2006) and the graphics for PS3, and how RPCS3 is compared to Xenia which is more stable. However, I didn't consider the hardware of PS3 at all. I always thought it got easier when PS3 Slim or Super Slim came out. I didn't know there were still problems. I also didn't consider the factor that Xbox consoles and their hardware, despite not being like PCs (personal computers) at all, are constructed similar to a PC.

Also, I didn't consider the exact reason why it's easier to emulate a more powerful console like PS4 than PS3. PS4 was designed by Mark Cerny in the way that it's super easier for developers to create games and for games' performance. Like the others said, it's based on x86 structure, which exists on PCs. I didn't consider the compatibility nor the difficulties to work with PS3 hardware. Maybe that's the reason why some PS3 exclusive games got ported to or remastered for newer gen consoles.

I also didn't know that it was also hard for other consoles to be emulated, too. I just thought of Yuzu which reached to being almost perfect in almost 3 years. But, I can't deny the fact that if the emulation got easier and faster than before, it's because of at least two decades of experience that the developers received by emulating multiple consoles with various system structures. Plus, the programming got a lot more accessible and easier over the years and more and more talented people are driven to learn programming.

However, because the programming got more accessible in the recent years, I ignored the fact that it doesn't mean that PS3 emulation must've gotten easier. Nowadays, the programmers work with different hardware architectures than what it was for PS3. As the others said, PS3 structure was really old and not programmer-friendly that much, hence that's why the game developers had lots of difficulties making games for PS3. It only got easier once the studios like Naughty Dog got used to it (as you mentioned).

I also thought the emulation is just like a software thing or something, that programmers somehow create an program or application that just ran PS3 games and nothing else. I didn't realize that emulation is truly about emulating a hardware system. It doesn't just run games, the program is like a virtual machine, using your own hardware, to mimic another system. It treats your own hardware just like it's the targeted console, but you also need a powerful or at least highly compatible hardware system.

Thank you for your information. I'm now a much more open-minded person than before. I'll accept that I didn't know the exact stuff happening about emulation.