The article says the world relies on fossil fuel for energy because it's cheaper. That's true. It doesn't mention that the world relies on it because it's reliable. It doesn't disappear for 6 months of the year, or stop producing for 3 out of 5 days or during peak demand periods. Make renewables cheaper and more reliable and they will replace fossil fuels in a snap. Cheaper is not enough if it doesn't do the job.
Right now, intermittent renewables actually drives up the cost of fossil fuels! Renewables do wacky things to the spot price of power - sometimes electricity is free or even has negative value, sometimes it's expensive. Ideally fossil fuel plants would only spin up when they could sell power at a profit, but they can't dispatch so quickly, so they end up selling power at a loss for minutes or hours after the solar panels or wind turbines kick back on.
This is producing market conditions that are favorable to batteries and super-capacitors, because they can dispatch in seconds, or milliseconds. Arbitraging between times of cheap power to times of expensive power can already be competitive with fossil fuels some of the time. And batteries are getting cheaper, too.
There's some question about what the ideal mix of generation vs storage will end up being. While storage is expensive, we'll tend to over-provision wind and solar, and end up throwing power away... unless we can come up for some use for it when we have moments of surplus. There's some talk of using it for things like ocean water desalination, but most of our machinery has such a high investment cost right now that the cost of electricity is not the biggest expense, so we don't actually have many machines that we idle until power gets cheap. Maybe that'll change eventually.