

im not sure how true that is considering that they can always just open a gate for fish to pass
That’s not how that actually works. Damming has huge impacts on downstream, now much drier, ecosystems. Even if there were a way to “open a gate for fish”, that wouldn’t solve the problem that their habitat is now gone. This is among reasons people have fought for dam removal. This also ignores the flooding of the environment that becomes the reservoir.
That wouldn’t generally be needed here, though. At least in the cities where most people live, they are walking and using public transit just to live, eat, etc.