Wow you're unnecessarily aggressive and oppositional. Who hurt you today?
FPGAs can absolutely be used to provide cycle accurate hardware replacements. The fact that they guarantee realtime execution of instructions also makes it easier to achieve cycle-accurate execution than can be achieved with emulation.
I'm not claiming FPGAs are a magic bullet, but when it comes to offering a retro gaming experience they offer a number of advantages for accuracy that is incredibly difficult to achieve with emulation, and with input latency far closer to the original experience than an emulator can offer.
Edit: Oh, and since you crapped on my parable, educate yourself with a Google search for "ntvdm"
A) I didn't use AI for any of that B) you're behaving like a pedantic dick and I'm done with you.