Jumping to the conclusion that "of course AI will get better linearly or geometrically because computers are" is making two fundamental errors: 1. it's assuming that the software/techniques grow like computers do, and 2. computers continue to get better in Moore's law fashion.
The first one is categorical error because software is, literally, nothing like hardware and the second one isn't going to happen (even the AI hardware peeps like Nvidia's CEO are saying this).