First off, try imagining yourself 200 years ago. It's 1823. The basic tech for lightbulbs has been tested but not yet refinded and commercialized. So you don't have access to electric light yet. You are still using candles.
You meet someone who claims to come from the future. He tells you that humanity will find ways to do truly miraculous things. He says humans will:
- be able to capture a visual snapshot of reality in an instant (Photography, 1827)
- communicate across entires countries almost instantaneously (Telephone, 1876)
- create a constant source of light that can be turned off or on in an instant (Electric light, 1879)
- effortlessly traverse houndreds of miles in a few hours with a tool soon to be available and affortdable for a significant portion of the population (Automobile, 1885)
- fly through the skies (Airplane, 1903)
- transmit a stream of images and sounds into the homes of an entire nation (Television, 1927)
- split the foundamental building blocks of all things to unleash absurd amount of energy (Nuclear power, 1942)
- land and walk on the fucking moon (Spaceflight, 1957 / Lunar landing, 1969)
What would your reaction have been? How high a chance would you have given these predictions to come true and come true over a timespan of a bit more than 100 years? Remember, you are using candles to light your home.
Artifical Intelligence, as the name suggests, increases our intellectual capabilities. Which already has and increasingly will speed up technological progress. So, if what I posted above was the speed of technological progess powered by human-level intelligence, what should you expect the rate of technological progress powered by superhuman intelligence to look like?
As to the second part of your post, the idea it won't matter for us even if it happens, I already made the point that: