Yep, it seemed right back then, it could do some nice graphics and sound out of the box, with no messing around with addresses, jumpers and such for your expensive Soundblaster card. If they had kept going, they of course wouldn't be stuck with the AGA chipset, would probably have followed the Apple route as at the time, PPC was the logical progression. PCs at the time were still very expensive for "multimedia" and gaming, and given another generation there's no reason why big-box Amigas couldn't have had PCI, and therefore not taken advantage of all the new 3D graphics cards on the market.
As for using external chip suppliers, why not? Look at Nintendo. PPC processors, graphics chips made by Radeon, yet it's still an individual machine.
