In what sense isn't it dead already? Transistors per chip, clock rate, and performance haven't doubled for several generations already. Take Nvidia GPUs, Intel CPUs, or Arm CPUs for instance.
You're right. The transistor count only increased by 90% every 18 months.
What's important is that they are increasing by a smaller ratio every generation; generations are taking longer and longer; and price/transistor is increasing steadily.