Everything in this comparison relies on the quality of data. The "number of innovations" data comes exclusively from a book by Isaac Asimov with under 1500 entries. To make some sort of grand pronouncement about a date range for the end of humanity based on Asimov's very subjective and unscientific qualification of what makes an innovation is absurd.
It's interesting that we think incremental improvement matters less than a brand new idea. Even steel tools built upon prior knowledge, and took decades to get right. Machines were incremental improvements from manually powered systems, which gradually evolved into the complex machiens we have now.
Some of these changed may feel like evolutionary innovations rather than revolutionary ideas, but that's how technology develops. It's easy to look at past innovations from the Greeks, because we see how the technology went from 0 to amazing. But we do it in retrospect, and speaking in terms of centuries, which makes innovations appear to spring out of nowhere more than they actually did.