What's being discussed here is not what a world without oil would look like, but "what would the economy look like if we pretend the energy sector doesn't exist, but we're still somehow getting oil from magical fairies".
If you were looking at the performance of the US economy lately and going "huh, it keeps going up and down, but some of that is 'cause of oil prices changing, what would it look like if they hadn't?" then this is the article for you.
If you were thinking about literally any other question (and especially the question of what the world might look like without oil) then this will be a puzzling waste of time; the payoff is just a graph of US industrial production over time excluding the energy sector.
(Spoiler: Recent fall in oil prices has not been good for the energy sector, but has been good for the rest of the economy, so if you pretend that the energy sector doesn't exist, then the "economy" looks better. Also, if you pretend that the unemployed don't exist, the unemployment rate is amazing. On the other hand, if you pretend Canada doesn't exist, it raises some very troubling concerns about maple syrup supplies. In other words, this is pretty fucking pointless.)