Whether tap water is safe in the US depends a lot on where you are. In general, it’s safe to drink in that you won’t get any serious illnesses like you might somewhere else.
Nobody will ever say “make sure the cups are dry when they serve you” or “don’t drink the bottle if the cap is already off” (because it’s probably been reused). There a few exceptions where that isn’t true. You can search Flint, Michigan and what happened to the people’s water there.
The closer you are to major polluters from the oil and gas industry, the worse it can get. But even most rural towns have fine water from a single purification plant or a system of wells.
More likely what you’ll get is that the water can taste funny, because the level of minerals may be more or less than you’re used to. A lot of restaurants will serve you tap water and it isn’t a big deal, but you can tell by the taste.
At a minimum, most people I know use something like a Brita filter attached to their sink or as a separate water pitcher they refill. Maybe something built into their fridge, though that can be worse if they don’t clean it properly.
I agree with this. There’s no predicting when it will stop. I think it will grow significantly from where its at, but then using Linux will be like using Firefox vs. Chrome. No longer weird, but never the standard or the thing most companies develop for first.