Its a little misleading.

Yes, if you are going by total volume, then it may be close to a reasonable representation. However, we live on the surface of the planet, 70% of which is water. That is plenty for everything on the planet, and then some.

And yes, freshwater is only 3% of the total, but it is a constant 3%. It never changes, because it is always being recycled as rain, vapor, and other biological stuff (you don't want to know...), and cycled from seawater. Water never gets used up. It just changes from one form to another.

The usable amount of water can change, however. It can be locked up in glaciers, as in the Ice Ages, or moved to other areas, leaving certain areas very dry, as in a desert. But the water is still here, somewhere.

There is no need to worry, unless we pollute it so bad we can no longer use it.