Why do you think technological gains will start diminishing?
Because pretty much everything is subject to the law of diminishing returns. Technology doesn't seem to be an exception here. We're running into limits of feature size on processors that are atomic in nature. You can't do sub-atomic transistors that I know of, and we're pretty much as narrow as we're going to get.
And, depending on who you listen to, we're doing a pretty good job fucking up the biosphere. Which we sort of need. The costs of that are going to have to be paid one way or another. Solar, wind, etc, aren't "free" either - they require very real resources out of the earth.
You seem like a pretty pessimistic person.
Comes with my line of work. Plan for the best, prepare for the worst. I'm literally paid to figure out what sort of bad things are likely to happen and to work out how to avoid those things, or reduce the impact.
Asserting "But TECHNOLOGY!" doesn't magically make it immune to the host of side effects, unintended consequences, and diminishing returns that everything else is subject to. So, no, I don't believe that we're likely to see the projected-in-article insane general AI any time in my life, or ever.
Maybe you're just blinded by day to day life to see just how technology is advancing exponentially.
In 1994, with a 66mhz computer, and about 8MB RAM, I could type documents, program, process data, and generally get done what I want to get done.
In 2016, with a quad core 2.xx ghz something-or-other and 8GB RAM, I mostly do the same thing.
In the 1970s, we had supersonic transports. In 2016, we don't. They weren't worth keeping around.
I can't say an iPhone 6S with force touch is particularly revolutionary over an older version. It's faster, but accomplishes about the same things. The original iPhone was a major change in how things were handled, but cell phones have been fairly stagnant the last couple years. Slightly better cameras, slightly faster processors going to do more fancy visual effects. Woo? At least we can chase Pokemon around!
And it's not like political systems are getting
more functional with time.
So, no, I don't share your optimistic view of the future as being to the stars. And, apparently unlike you, I'm spending a bit of time and energy preparing for what happens if that future doesn't happen.