I don’t understand the focus specifically on water bottles when this comes up.... I understand we don’t all have pipes that bring Coca-Cola to our homes
It sounds like you do understand the focus on the bottle that's easily replaced by opening a tap or using the water fountain that's found in most public places.
Likewise there's a lot of focus on replacing light bulbs with energy efficient alternatives, and less focus on replacing electric space heaters because light bulbs are easily replaced with little impact on the user (and indeed, save money over the long run) and are more common than electric space heaters.
It sounds like you do understand the focus on the bottle that's easily replaced by opening a tap or using the water fountain that's found in most public places.
Likewise there's a lot of focus on replacing light bulbs with energy efficient alternatives, and less focus on replacing electric space heaters because light bulbs are easily replaced with little impact on the user (and indeed, save money over the long run) and are more common than electric space heaters.