We're not really adding much more fossil fuel capacity. 88% of new capacity under construction in the US is renewable. Of the fossil fuel capacity that is being added, it's overwhelmingly coal-to-gas conversions and peaker plants that help to deal with the variability in renewable generation.

It will take a long time before the fossil fuel capacity we've already built gets phased out, and of course certain developing nations are still adding dirtier fuel sources, but renewables getting cheap is working.