I'll spell it out for you.
Obviously you're struggling with this passage:
Although rainwater and ice are not used as community drinking water sources in industrialized countries where drinking water regulations were developed, they are used by individuals in some locations.
If I have a community of 100 individuals - a rural village, and that rural village is decentralized, it has no centralized supply of drinking water, and no centralized sewer system.
Because there is no community supply of water the statement "Although rainwater [is] not used as [a] community drinking water source in industrialized countries" is still true - if there's no centralized supply, there's no community supply.
And the statement "[rainwater is] used by individuals in some locations", and so my statement that "And yet, in developed countries all over the world, people living in rural environments with no usable aquifer use tanked rainwater on a daily basis" does
not contradict what the report says. The two situations being posited are completely different. I was referring to a group of individuals whom rely individually on tanked rainwater, but live as a community in a rural or rural-urban environment. The WHO report, however appears to be referring to the scenario where a community relies on a centralized water supply collected exclusively from rainwater.
Do you understand the difference?