The claims sound truthful ...
with your typical caveats/lies included (ex 0 calorie per serving might be 0.5 kcal)
they're just leaving out the important part,
it only removes tiny tiny tiny tiny trace amounts of contaminants in city water
The kinds of trace amounts that show up on your city water quality report --
if water is too dirty (like car goes into reservoir), the city switches sources, they don't try to filter it

Its like refrigerator filters, sure if there is a boil water order your filter might help, but mostly what they do is improve taste

if there is a flood/storm... and a full tank of gasoline goes into your swimming pool ... your water filter might get you a gallon if you're lucky

Just to give you an idea, I read a filter lab report last year, a bacteria/virus and carbon + other stuff filter that could remove diesel/gasoline ,
good for 1000 liters,
can you guess how much diesel/gasoline it removes?
less than one teaspoon
0.04531 fl oz (fluid ounces) , 0.2719 tsp/teaspoons, 0.09062 tbsp (tablespoons)
0.08487 fl oz (fluid ounces), 0.50922 tsp/teaspoons, 3.9 x volume of a (plain) M&M candy (0.64 cubic centimeters)
So filter could handle 1 gram diesel + 1 gram gasoline + 1 gram pesticides in 1000 liters of water
They spiked the test water with 1mg/L gasoline but their testing threshold is 0.2 mg/L, so there could have been 0.19 mg/L gasoline left

FWIW, activated biocharcoal is not too hard to make