Imagine someone said fully autonomous self-driving vehicles were inevitable. Why? Well, we've already made "superhuman" vehicles—cars, planes, boats and trains are all capable of moving much faster than humans.
Like, we may still get fully autonomous vehicles, we may not. (I've got the already existing alternative: a city with a good public transport system.)
But "a car is faster than a human" is as irrelevant to the point as how many teraflops a CPU can do is to the likelihood of AGI.