The Mac graphics cards were used for things other then gaming. I have a couple nice Supermac Nubus cards (one of which is in my IIfx) that can do 1024x768@24bit and are speedy with redraws all at a 80Hz refresh and it also has a DSP daughtercard for photoshop filters and other functions. It also has 4 slots for GWORLD ram with is basicaly extra ram used to buffer the screen not shown so that you don't have to go fetch it again over the bus when panning around.
Apple sold its systems to printing houses, graphics shops, photoshop, and video capture companies. Gaming was never big with Apple macs. So its hard to compare an Amiga to a Mac since they were built for different things. I do think the Mac aged much better then the Amiga did with respect to resolution and color depth which we take for granted today (plus using common VGA monitors instead of cranky old TV resolution monitors).