Hydroflasks are some of the best in the game, but some hikers use them sparingly because they are quite heavy. However, they offer a lot of other benefits that compensate for the heavier weight, benefits which some hikers.
After all, you want to move easily and efficiently through the wilderness, so having a lightweight water flask is vital. This is because bulky, heavy water bottles will slow you down and make it difficult to carry all of your essential gear.
A lightweight flask helps you avoid carrying excessive amounts of water, which can unnecessarily drain away valuable energy.