From an outside observer's point of view, I say: no.
But with that said...
The custom chips were used because there simply was no common powerful graphics solution at the time. The tricks and twists and turns they got to make the Amiga capable of what it was were really not that different from what coin-op arcade game manufacturers were doing, in that every time they came up with a new game, they, at the same time, built a custom hardware solution to realize the game. Heck, the first few Centipede machines from Atari were all hand-built!
But the point is, Hi-Toro/Amiga didn't have a PCI or even a 16-bit ISA bus to put things on; no VGA (forget the "S"!), and so forth. The thinking at the time was to build a specific solution for a specific problem (in the Amiga's case: How do we get high-end graphics on a desktop computer? (or rather, game console)).
If there had been no "Amiga" then, there would never be an Amiga. The BeBox was the closest anyone else came to a consumer-level custom hardware + non-x86 OS solution...well, once Apple gave up on their proprietary systems, e.g. NuBus etc.
Ultimately, when confronted with "What is an Amiga", both sides are right. It IS the OS and it IS the custom hardware. As much as I hated metal-banging trackloading single-floppy "won't work with anything but a PAL A500+" games, the same custom chips made good things like the Video Toaster, DCTV, countless Genlocks, and so forth possible - but the OS was a huge part of that as well.
Consider this, all you OS only people:
The Video Toaster won major awards at the NAB conference, and was selected as the peripheral of the year at MacWorld the year it was introduced. The second one is quite hilarious since the "controller" that allowed you to use the VT with the Mac essentially lobotomized the Mac and used it as a dumb terminal for the '030 Amiga underneath!
Likewise, the "hardware all the way" folks who want a new and improved AGA chipset with 80,000,000,000,000,000,000 sprites, copperlists that would reach to the moon, a SuperDuperUltraMegaKiloGigaDenise - and backwards compatibility with OCS - need to understand that had the VT's software been tied specifically to the Amiga's chipset, LW might well have never made such an impact as it did. Likewise several other 3d packages.
But that's just me - I could be wrong...
