I try to avoid using individual plastic bottles of water as much as possible. It's horrible for the environment.
I don't think there's anywhere in Europe where I didn't drink the water, and I've never had a problem.
In Mexico, Central America, Southeast Asia, and South America I didn't drink tap water. Some places have big dispensers in the lobby where one can refill cups or bottles. This was the case in the Galapagos, for instance. In Hoi An and in Hanoi, Vietnam, the hotels provided a bottle of water per person per day, which was nowhere near enough. In Hoi An, we bought a large bottle of water from a shop and refilled our insulated water bottles from that. (We did see someone selling large bottles on the street that had clearly been refilled, so even from the store, we were careful to make sure the bottle had not been previously opened.) In Namibia, our guide brought a big container of water for us to use to refill our metal water bottles (that he provided). If we were someplace where he said it was okay to drink the tap water, we did so.
I've also used a Lifestraw bottle and, more recently, a LARQ bottle if I think it might be iffy.
My rule is that if there are warnings about drinking the water, or if the plumbing infrastructure is clearly not great (e.g. can't flush toilet paper), I don't drink the tap water, but individual plastic bottles are still a last resort for me.
Taste hasn't really been an issue for me, but if it were, I'd probably see if my LARQ bottle improved things, or, again, I'd buy a big bottle and refill my LARQ from that.
(BTW, in North America, a lot of bottled water is just bottled tap water, although, of course, the tap water tends to be safe anyway. But I'd rather have it from the tap than have water that's been sitting in plastic for who knows how long.) https://www.latimes.com/business/story/2021-09-28/bottled-water-is-really-just-tap-water