Well, let me ask you a question: has literature reached its pinnacle? What about painting? Theater? No? Neither have games, because I honestly don't consider it to be possible.
Now, just to make sure we're on the same page, here, my definition of "pinnacle" is "perfection": as in, "We have reached the absolute peak of what is possible with our medium, and there's no way in hell we can ever do better." And that's straight up impossible. True perfection is nearly unreachable, even in theoretical matters (where's my 100%-efficiency engine, SCIENTISTS?), and when you add in subjectivity, where everyone has their own standards for what constitutes the pinnacle of excellence, you just can't please everyone to the point that everyone agrees it's perfect. And that's the way I like it. I don't know about you, but I find the idea of truly reaching perfection to be absolutely depressing. Imagine playing a game so utterly amazing, that every other game in existence feels like playing the Starship Troopers video game while a black-belt kicks you in the groin- I can't help but feel like life would be unbearable after that, because THERE'S NOTHING LEFT.
So long as perfection remains just out of reach, people will continue to strive for it, and will continue to make amazing, wonderful things. And I'm looking forward to that.