Please correct me if I am wrong in any of this, as I have a rudimentary knowledge of battery/capacitor/flywheel/Cox's timepiece tech at best. Li-ion make sense

Please correct me if I am wrong in any of this, as I have a rudimentary knowledge of battery/capacitor/flywheel/Cox's timepiece tech at best. Li-ion make sense for supplying power for things which need Ah/kg high, but if you are not limited by mass, wouldn't maximizing aH/$ be the driving factor? Tesla has been making a massive push into li-ion fabrication and, as far as I can tell, not pursuing other energy storage mediums. Totally speculating here, but I would imagine a fly wheel, or even banks of lead-acid batteries, way out performing li-ion on total lifetime costs to the energy stored and discharged.