As years went by, new caffeinated beverages started hitting the shelves, such as Josta in the mid-90s (the US's "the first legitimate energy drink") to Bawls in 1997, to the permutation of other caffeinated products such as gum and soap that were short-lived in the early aughts. Finally, the beverage market reached its peak as "energy drinks" finally broke away from sodas altogether in the public's eye, maintaining their image as a beverage for thirsty nerds and gamers.
The c64's legacy is much like Jolt's. It has since been replaced by things that are in the same spirit for the same reasons. Diet Coke was never cool, never tasted good, and was never an icon for anything like gaming, gear, or geekdom. It can take a hike.
My understanding is that Diet Coke is based on the failed "New Coke", and Coke Zero is based on "Classic" coke.
2. Diet Coke has changed its recipe eight times in the described timeline
3. There are currently six zero calorie Coca Colas. The most popular isn't Diet Coke. It's Coke Zero. They taste very different.
4. The tongue is not following the recent invention of transistors
"improving" on a food/drink is highly subjective. In fact, Coke tried it themselves, ending in the "New Coke" fiasco: https://en.wikipedia.org/wiki/New_Coke
Diet Dr. Pepper is the only thing worth a damn.