In a tent or snow cave at 3 am or in a storm, a container does offer some comfort by allowing you to stay inside and minimizes tracking snow back into the tent.
And, while caving, all water bottles are bi-directional (leave no trace).
We often drive to the trailhead, so there’s the road-trip use as well.
But, again, plenty of short, decent-volume, lighter options in the recycling bin for free.