Why would Amiga hardware be destroyed? I don't understand. Who goes smashing these hardware?
Just like old cars, they get old... and unless you repair them, replace parts,... they are destroyed.
Anyway, UAE clearly outperforms real hardware, and have been since a long time. There's no need to argue. Of course, display is a little different than on the real thing, timing may have tiny differences. But seeing what you gain in exchange (speed, flexibility: in a single click you may be running any OS version/rom you want, any hardware: 68000 up to 68060) I have no problem saying that UAE replaced the Amiga for me. I'd be happy to play with the real thing for some time though, but having to have one expensive one myself, no way...