Others have said it. There is the I drink from it all the time, and the never drink from their tanks. Depending on my trip/use I bring 1-2 5 gallon water cooler jugs of water for drinking and the dogs. There is usually a case of bottled water for quick convience of grab and go, and that case lasts several trips.
I do this for one reason only, my dogs. When I first started RVing, I drank the local water or from my tank all the time. I figured as long as I ran the water after hooking up and kept my tank/lines clean I would be fine. But then it seemed like every trip my two dogs where getting sick, I replaced filters, my hoses, sanitized everything. And the next trip, same thing for the first 3 of 5 days. Moved to our next location, started all over again. Since moving to the water cooler jugs, I no longer have that issue with the dogs and I have noticed less issues myself in the change in water. Otherwise, I use the local water or my tank for everything else.
I am sure if I where full timing and spending long runs in each location, it would be less of an issue. But right now its random weekends and a 2 week trip every winter and that seems to make a difference.