Liquid tea is bad for your teeth, isn't it?

I often drink this type of beverage

I just found out it's liquid tea ^^;;;

No matter what, the water is the best...

Actually, it doesn't really work...

But even if I drink something like this, I still need to brush my teeth, right?

Since it's a liquid tea, I suppose it's only natural, but

It seems a bit ambiguous.

For one thing, I can see the sugar content in the nutritional information as well.