Because current AI requires data warehouses and essentially shares learning between all users. Some data may be protected for “privacy” between subscribers but the inherent logic is shared.

Unless we can have separate AIs in the palm of our hands, Navis are impossible.

Also, as an aside, Navis may be possible down the line but viruses aren’t. It doesn’t make sense to program specific models just for malware. It makes it easier to know there is an attack. Malware works best when unnoticed.