[forgetsusername]

>WHY does this problem still exist, considering all of the resources at FB's disposal?

It might have long-term implications on their actual business, as people learn that the advertising isn't worth it but no one likes to think about that. They'd rather focus on "more important" long-term things, like VR and confined internet in second world countries.

In the short-term there is no incentive to solve the problem. Facebook has been boasting about membership usage since day one, when anyone who has experience with the ecosystem (ads or apps) knows that these fake accounts are a massive issue. But they allow Facebook to say, "1 billion people* use us every day!"

It's clear from the responses you received that it's nothing but lip service about doing something regarding fake accounts.