2 billion people rely on quickly melting glaciers, a lot of water tables that depend on rainfall aren't being replenished at the rate they're being emptied.
You can cover your ears and ignore physics all you want. If you take out more water from an ecosystem than what is coming in, eventually you run out.
Sure, and the people who live near oceans can just sell their houses and move as sea levels rise.
People forced to migrate due to fresh water scarcity will migrate to where fresh water can be found, which is likely where other people already are, increasing pressure on the increasingly scarce water and other resources in that area, driving conflict, disease, famine, further migration into increasingly stressed areas and leading to social and ecological collapse across the board.
Access to reliable fresh water is foundational to stable society.
Look at what's happening in Sri Lanka or the middle east (drought causing famine was a catalyst to the arab spring) for an example of what happens when people try to move elsewhere.
Is this statement a version of "actually, there isn't a problem"? Because if you're dismissing what's happening, all I can do is implore you to look into this issue with a curious and open mind.