I don't quite get the point why there's any room between the two for anything "more novel but still obsolete", and PPC hardware *is* obsolete, either because it is old (MOS) or because it is "obsolete by design" (AOS). If I'd like to reach out for the Amiga community (rarely these days), there are still the 68K machines, so I don't need them for that.
There are two good reasons.
If you are using real Amiga you must patch OS and install upgrades.
If you are using real Amiga you must patch HW and install upgrades.
With MorphOS you just buy some $20-$200 HW from ebay, install OS from USB or CDROM and if you like it you register it online. That is Amiga made easy.
Real Amiga can do same but personally I am not ready to invest my time and money to get it there. Not anymore.
I had to sacrifice some level of compatibility, I can only run RTG compliant software on it. But it was not great loss because my Amiga 1200 could run only RTG compliant software anyway (I didnt have TV available to Amiga).