I might sound rude: but.. if you ask. do it yourself and you will notice that it is not that easy.
It is kind-of rude, but kind-of not. What people who understand things often fail to understand is there are those out there who see things at a different level and while they may have a basic grasp, the leap from one level to another level is a larger task than that for others. As such, we often defer to those who understand better to shed light on the matter.
While I like to encourage others to learn for themselves, sometimes it might be the nudge of information that helps. The "do it yourself and find out" answer is off-putting to those who are genuinely curious.
I, too, wonder why AGA has not yet been replicated, and considering the minds which have been lent to the task I postulate there must be a stumbling block somewhere which has yet to be surmounted or possibly, like you say, maybe RTG is just easier. My limited understanding of the matter leads me to believe that replicating AGA may not be all that desirable in the first place considering the obvious and observable limitations of the AGA chipset compared to what is possible with RTG.
Anything more in-depth and technical than that, well, Amiga is a beloved hobby of mine but I have to spend the majority of my day earning a living so deeper investigation, while tempting and tantalizing, is simply not practical, and if someone knows more than I do why re-invent the wheel?
