VGA mass adoption was the key. EGA Cinemaware games will forever be inferior to Amiga versions even on an running on Intel i7 920 PC today. After VGA though it was game over.
That about nails it. Word processing? You really want to do that in hi-res laced on a 1084?
I remember when I got Dune 2 for my A500. I went to a friend's house to check out the PC version, and left pretty ruffled. All the games had better sound, more colors, higher resolutions...
Then the mid/late 90's, after C= tanked... Competing "standards" (each with their own bug-ridden patina), vaporware, over-priced, unfinished, flaky products like the Delfina and CS-PPC, pre-order scams... You had to be a real gambler back then to "keep it real". :-/
I enjoy computers in general and always have, so there's no hit to my "true-amigan" status to acknowledge reality. I still use Amigas on and off in life simply because I find it relaxing and enjoy the learning curve. The PC did some things better, so what?