The problem with the N64 was that it sacrificed everything for solid geometry with stable textures, and the removal of visible pixels. The theory was that instead of looking like a videogame, it could look like the worst CGI ever made. Especially if you aimed for a decent frame rate.
So nobody really expected one. Goldeneye was a critical darling despite frequently stuttering through a simple gunfight between angry blocks of blurry cheese. Ocarina was clocked at 20fps or less, which is a war crime according to modern Youtube experts, yet it was unironically crowned the greatest game of all time by the kind of people who think you can objectively rank different game genres against each other.
Besides, breaking the frame rate in Turok 2 helped sell the power you'd unleashed.
And that's an important bit of historical context for understanding why 9/9/99 was such a big deal, at the time.
Because all of this gamer understanding and forgiveness was immediately forgotten the moment the Dreamcast launched. Suddenly, the only thing that made N64 graphics stand out were their negatives. Compared to a 640x480p standard, with no loss of frames, and more polygons per character than most games had in the entire frame? It really felt like a revolution. And in many ways, it was.
It nearly killed arcades overnight. Can you imagine the poor suckers buying a Soul Calibur arcade cabinet for the price of an expensive PC, only to see Soul Calibur on Dreamcast completely destroying it a year later? Nothing Capcom or Midway was doing even came close.
Suddenly, the arcade went from being the place you went to see the future of gaming, to the place you went to remember its pixelated past. Or to earn redemption tickets. Sure, there were a few exceptions - the Dreamcast couldn't compete with Sega's own model 3 board, but not nearly enough. Even when the new console couldn't compete with a new arcade title, the differences were usually subtle. An open jacket in VF3 might not be animated when a character moved, but it wasn't the same as watching a Saturn try to fill the empty void where a Daytona track should be, at only half the resolution.
We should have known then, that it was the last time we'd ever experience that kind of a dramatic graphical leap between generations. The launch of the 360 wouldn't compare to the party that was 9.9.99. And that's not just my opinion...
Hard as it is to believe a decade and change later, when everyone's obsessed with how stable a locked 60fps really is, and dissecting expensive AAA lighting engines, it used to be easy to find reviews of early 360 titles where the reviewer can't describe what makes the games look next gen, except when they directly compare it to a previous gen title.
It's a charming bit of innocence. At least for the brief moment in time that it lasted.
Too bad it got a lot easier to tell the difference once every AAA publisher decided they'd wage a war against blue skies and feel good emotions. Maybe it's a good thing Sega stopped making console hardware when they did? They were able to go out on their own terms, making the kinds of games they wanted to play themselves. It's a legacy anyone can be proud of.
Best of all, it meant that most of Sega's efforts to ruin that legacy ended up on the competition instead.