For new builds, I think we're beginning to see accelerating encroachment of renewable + storage on the low capacity factor natural gas plants. For short timeframes it looks like the existing cost reduction curves for PV, wind, and Lithium storage seem likely to grow to completely knock out the competition for hours to days level of intermittent supply.

https://www.greentechmedia.com/articles/read/record-low-sola...

For longer time periods, and comparisons vs existing plants, I agree that the economic changeover point will be less clear except that turbine tech is basically on the matured portion of a manufacturing S-curve, while PV, wind, storage are riding the downslope.