I never liked replacing water filters everytime they expire.
But I don't trust UV 100% either... What if it mutates a microbe, making it stronger instead of killing it? Combination is best, like chemical and boiling
It also makes me wonder, people who are so reliant on their phones that they can't resist charging it with a hand crank, will ever be in the wilderness? I mean, a guy in an accident won't have energy to do it, a guy stuck somewhere, won't have time to do it.
Btw, my approach to multipurpose device is a waterproof ammo can style box or pounch with
2x 11000mah power bank, (smaller 2500 mAh for pounch)
a USB plug sized laser 100mW that I made.
A USB 1w flashlight with lens
Lighter (waterproof,alcohol)(I can weld, do blacksmithing etc etc but I still burn my hands every time I use match sticks
)
Thick thread
Cyanoacrylate glue
Stylisation pill, that I might replace with UV thingy
A Leatherman
I might pack a fire cracker for animals
To boil water, use the can itself (empty it first
)