All forms of energy have major problems, especially at our gross levels of consumption, but hydroelectric is probably the least shitty method as far as poisonous/cancerous toxicity is concerned.
The "teslas will save the earth" is 100% a drunk jonestown trumper qanon mentality in that it completely departs from reality. People want them to take over, but forget what 300 million teslas looks like. That's 360 billion pounds of battery. And if you want full-e use, that's about ten 250w solar panels per car to charge them everyday, which is 3 billion solar panels, and at least as many pounds of silicon. Then there's the other 3000-4000 pounds of the car times 300 million cars to deal with. Oh and if you look at the curve of growth over the last 50 years, by the time the obese electric hummer tesla style takes over, it's not 300 million anymore, it's 600 million and everything doubles.
The problems all boil down to our culture, in that, freedom is akin to using as much energy as we want, having as many kids as we want, and buying whatever we want. In many EU countries, they culturally pride themselves on minimalism and efficiency. That will never be us, which means that our path will be much more painful.