A very simple Commodore Amiga question

Amiga ball

What does have even the most ridiculous Amiga 500 which is preventing any of the emulators around there to work properly? Why there is not a single emulator which works decently? I tried to see a pair of old amiga demos (well, basicly State of The Art), and I couldn't stand that slow agony for too long... I know Amiga had several dedicated processors (Paula and so on), but it had around 16MHz processor, and we are talking about emulating it with machines of more than 1000 Mhz, which also have their own dedicated chips (graphic card, sound card).

We have seen good Megadrive, SuperNes and even NeoGeo emulators... all of these machines had their own dedicated chips for sound, graphics, etc, if I am right, so something is going wrong here... I'd like to listen any kind of explanation, as I think I'm missing something for sure :-) (and super greetz go to Humphr3y which I am sure that will like to know why as well, as we commented about this issue some time ago)