Thus far, Niantic has issued punishments to over 5 million users caught cheating, leading to more than 1 million permanent bans being levelled. While those numbers are spread over all of their mobile AR titles, Pokémon GO, Ingress, and Harry Potter: Wizards Unite, it's still an almost unbelievable figure. That said, the situation may not be as bad as it first sounds. Niantic encouragingly pointed out that over 90% of those they gave warnings to stopped cheating afterwards. They consider this a success as they "continue to find the right balance between punishing casual cheaters versus the more egregious ones."
The struggle between hackers and developers is unlikely to ever end, and both sides are constantly evolving their methods and deploying new tools. Should Niantic's efforts with the Fast Track trial for Ingress players "which would enable them to request for a quicker manual intervention." prove effective, it's likely only a matter of time before a similar program is rolled out in Pokémon GO.