The problem with hardware is that it is scarce, and ultimately dies.
The problem with emulators is that they emulate. We can work to make it the same, but it is never going to be the same.
Even if the math all maths just like they did (bugs and all), and it takes precisely as long, and it shows up precisely at the same time in the same places as it did on the original hardware...and even when things like input latency are nailed down to nanosecond accuracy and the clocks are all just dead-nuts on: The code may run the same way, but the system is still not the same.
Part of the reason it's not the same is we haven't even touched the analog components yet and all and all of the things they do, whether amazing or ugly. (And no, improving the analog bits through simplification is not necessarily the sane goal at all. Improvement and emulation are different targets.)
Emulation is useful. It's great, actually. Right now, a person can think about that old PS2 they used to have and get started with playing some of their favorite games yet this afternoon. That's awesome.
But preservation, as an effort to keep old hardware to keep working as time marches on? That's a wonderful thing in its own right. The better we understand the old hardware, the more-able we are to preserve it and keep it running.
Getting past the layers of deliberate fuckery helps us to better understand what goes on behind the curtain, and that has now been achieved.
Most discs do not rot. The panic around disc rot has not materialized in discs actually rotting outside some edge cases like faulty manufacturing.
In a few decades everybody who played the PS2 upon release will be dead, and our descendants will not care if the emulation is 100% accurate or just 99% accurate.
Not always, of course. To be very kind: Some paintings are just shit, and some structures are architecturally regrettable. And sometimes, the juice isn't worth the squeeze.
But not all things are regrettable shit. Some things are found to be worth saving, and are therefore saved.
You're free to disagree about that, and you certainly don't need anyone's permission to hold any position you wish on any matter at all.
But others are also free to form their own thoughts and opinions and it is very clear that they don't always agree with your own.
Apparently, there are people in the world who still care about the PS2. They are likely to continue to do this kind of work whether you find their efforts to be valuable or not.
From what I can tell, this opens the door to things like optical drive emulators, which replace the disc laser with an SD card slot, allowing the console to read game disc images no differently than the console would read a retail game.
So things like making a clone of the hardware with an FPGA, making emulators cycle-accurate, removing game-specific hacks that are no longer needed due to more accurate emulation, and achieving 100% bug-for-bug compatibility with original hardware.
Far from it. PCSX2 is extremely solid for casual playing, but it takes a lot of shortcuts (especially when enabling upscaling and other enhancements) that differences both in gameplay and visuals in games like Gran Turismo and Ace Combat are extremely evident, more so when framebuffer and/or shader-like effects are applied.
Mind you it's not a game-breaking experience, but I feel it's differently enough to be considered closer to playing a port rather than an emulated version of the game.
The PS2 is unfortunately too alien of an architecture to expect BSNES-style accuracy AND an acceptable framerate.