Processing power hasn't been a bottleneck for a long time. Even the 4MHz Saturn processors were able to do reasonably fast 3d wireframe graphing. The only reason graphing calculators and scientific calculators still exist outside of schools is because they can provide a specialized user interface: a physical keyboard with a layout designed around calculation tasks, and a software environment that is similarly optimized for that narrow range of use cases. Neither of those aspects benefits significantly from Moore's Law. Instead, they can only benefit from the complementary products that other gadgets have made commodity components: high-resolution displays, lithium-ion batteries, SoCs that replace ASICs and make features like USB and SD support free.
