AFAIK Jay Miner&al desigend the whole OCS,... themselves. That means sound, graphics and everything. Specialized GPUs like Voodoo for the masses came about '94. Designing those isn't trivial. It is even worse than making CPUs. Not to mention ISPs for sound and such.
Commodore would soon have had to implement PCI bus or find new business partners. Things were not running in favor, even if there would have been billions on the bank.