I can't speak for every PC ever built (there's always soemone who seems to come up with something "unusual" in these threads), but I can honestly say that compared to the PC's I've used and seen used by other, the Amiga could do more (FAR more) with far less.
An A1200 running at 14 mhz and 8 mb fast ram could fit a TCP stack, a browser, an email client, newsreader, an FTP client, IM, a paint package like Dpaint, a word processor and even do a 3D render in the background ) especially if you had an FPU, play music/mods, a file manager like Dopus on top of a GUI OS-with god knows how many little commodities running in the background and the thing was still responsive to the user. I can't imagine any x86 platform doing that.
I'm not sure if that advantage in the efficient use of hardware resources was there by design or as a consequence of little hardware development since Commodores demise, nor if that would have continued if AmigaOS survived today. But what has been achieved by tiny teams of programmers with Morphos/AmigaOS/AROS suggests it might have (yes I know they run on limited hardware, but thats what custom chips were in a way).
So for me, Amiga was all about efficiency, elegance and making me feel that the system obeyed me, and for me that made up for the lack of the brute power of a PC.