We are actually doing that, though. Across the globe, the fraction of energy generated by non-renewables has been falling consistently for more than a decade. We went from being less than 5% solar + wind a decade ago to more than 10% now, and the trend is accelerating. By 2026 we're expected to be nearing 20% of all power generation renewable. Things aren't going fast, but infrastructure doesn't go fast, and no proponent of renewable energy expected it to.
I think this is in no way comparable to the symbolic learning thing where there is no sign of relative progress.
As far as the hard cap you mentioned, I think there's no danger of us hitting that cap in the next decade or so. Later on, maybe. Battery technology is also improving rapidly, so perhaps it will never be a true limiting factor.