Not to argue with your point because it is certainly valid, but the N64 had that expansion module for DK 64 and a few other games, yet managed to survive that.
Most of the games with epak support used it to increase quality and / or framerate, the game worked fine without. It was also relatively cheap ($50).
Which is kinda impressive (for the time at least) considering how expensive RDRAM was/is relative to e.g. SDRAM.