Another is to avoid cotton, it soaks up water and makes you heavier which can slow you in difficult conditions.
Polyester is a good example. Not to be used when fire is a risk, then leather or cotton is better. I have a windproof material top+bottom as they then block sunlight if forced to be outdoors a long time, stops most insects biting if in a hot humid location, and blocks heat loss if you are in a cold windy situation, these garments I pack as an emergency spare set.
I would not carry an empty waterbottle, I tend to aim for 2L-3L of water, adds 1Kg/L but it covers you til you get to a water source, note those straws typically block bacteria but not viruses usually so a good idea to fall back to straws if desperate, usually you can get emergency services to supply water in a day or after the cause of the problem has passed so usually it is a day's worth of water you should carry, which in active in cold is about 1L, active in cold is 2L, inactive in hot is 3L, active in hot is (a much bigger number, 8L but carrying 3L gets you to still alive as you lost only 5L). Obviously that filled bottle is empty when you then use the straw. A straw is I agree the best solution but if you wanted to handle bigger problems, then using gravity between two bladders is physically easier (fill dirty bladder, hang from height, straw, clean bladder lower down, wait). The straws which filter viruses are slower so gravity filtering can block viruses.
The Water problem is subtle, as is the Anker benefit.
If you track the history of those who almost made it to survive vs did not, it often tracks to sunshine and water. The human is weird in that the human's unique benefit is the same as its biggest weakness - the big brain. A human can think itself out of a problem, but also think itself into a problem. Water, the lack of, thirst, focuses the mind on making otherwise irrational risky decisions. Anything you can do to stop thirst helps think straight and do the obvious thing.
Anker's benefit is mostly related to that brain, that you can "chill" and not over-think a mild problem into a major problem, you can listen to music, watch a video, feel distracted away from your problems so you do not think the problems bigger than they are and so not overreact. I think that is probably Anker's core advantage, you can carry music, a comedy film, a documentary, something to read, and keep those things going for days (weeks if you add with solar) to keep yourself proportionate to the problem.
A little bit of Anker in your life....