HDPE Nalgenes (branded "Ultralite") are my standard water bottle. Unlike the clear plastic sort, they're not see-through, nor very heat/impact resistant, but they weigh next to nothing. Just don't use 'em as a hot water bottle.

Same here, although they sadly discontinued the narrow mouth version.

The soft HDPE bottles are actually more heat and impact resistant than the rigid clear polycarbonate ones. They’re the standard recommendation for winter hiking.

https://momgoescamping.com/water-bottles-insulators-winter/

Honestly the water bottles are probably fine as they likely don’t leach much BPA unless something happens to break the polymer apart- like contact with a strong chemical solvent. Although BPA is an endocrine disruptor, it is likely that normal use of a polycarbonate water bottle is fine. They stopped selling them because people got afraid and stopped buying them. I still see no reason to use one given the uncertainty.

You can get really good HDPE, stainless steel, and glass water bottles with a silicon impact cover.

There's an argument that polycarbonate is very well-studied and the BPA released is low, while some of the alternatives have unknown risks.