Yes, outside of some dictatorship nations it is very hard to build new hydro dams these days. To be fair the impact to real estate values in general usually more than the economical benefit of hydro power reducing electricity price by a few cents per kwh.Always look out for the writers. Many are English majors, not technical people.They freely go with back and forth between BEV’s and Electric Vehicles. Electric vehicles include hybrids in the count as well as BEV’s.
Another beef is that Hydro is tucked in nicely to give renewables a nice sounding 20%. The vast majority of hydro is from huge power dams built in the last 90 years. Subtract that and renewables are back at about 13 %.
However, with the right charging schedule and a big enough battery (that will last at least 3 days worth of commute, so you can charge based on price rather than you must charge at all cost to get to work tomorrow) or being a plug in hybrid, this "cheap wind and solar are unreliable" can be tolerated during heatwaves (i.e. you can at least charge between 1am to 8am without blackout). If your grid is so bad you get a few days of blackout, then you probably live somewhere that you need to at least get a plug in hybrid instead of an EV anyways.