You are correct the first use of any new technology is niche with highest ROI. The $trillion dollar market to replace fossil fuel has attracted massive investment in battery, wind and solar, continuously driving down cost and expanding market segment coverage. The projected saving are after 3,or 4 more generations of development- so not todays products. 90% reduction in battery price over last decade is on track to drop another 90%. See CATL sodium battery and Si anodes for recent examples