Also: I think it got less common on the N64, but games on SNES and NES and other old home consoles routinely accessed static game data, like graphic tiles, directly from the cartridge ROM. Without loading it into system RAM at all.

So there literally were no "loading" times for these assets. This might not even be realistically possible with NAND flash based SSDs, e.g. because of considerations like latency.

Though directly accessing ROM memory would also prevent things like texture block compression I believe.