Only for some applications, hopefully stationary ones.
Don't expect power density miracles
Incredibly, you can already buy Sodium-Ion for very reasonable prices from Dongguan GoKWh. Sure, power density is a bit lower than LiFePO4 but look at those $50 motorcycle batteries which can be direct replacements for lead-acid in many climates.
This is only possible because you can charge Sodium-Ion down to -10°C/14°F. EVs using lithium chemistry have to run a heater until the cells are all above 0°C/32°F before they will begin charging, greatly extending charge times in subzero weather. And there are of course many stationary applications where the heater requirement would waste many of the limited hours of solar you can get in the winter. With demand for batteries projected to rise rapidly,
any alternative allows lithium to be reserved for more high-performance uses.
What kind of environmental horrors would this extraction unleash?
As with oil, the most easily extracted forms are obviously collected first before you resort to more difficult ones like shale oil or this brine. And fracking is commonly used to extract brine from deep rock so expect the usual earthquakes and aquifer contamination.