The graph actually looks like it’s saying the opposite. Fro most of the categories where there’s actually a decent span of time, it climbs rapidly and then slows down/levels off considerably. It makes sense also: when new technology is discovered, a breakthrough is made, a field opens up there’s going to be quite a bit of low-hanging fruit. So you get the initial step that wasn’t possible before and people scramble to participate. After a while though, incremental improvements get harder and harder to find and implement.
I’m not expecting progress with AI to stop, I’m not even saying it won’t be “rapid” but I do think we’re going to progress for the LLM stuff slow down compared to the last year or so unless something crazy like the Singularity happens.