In general it is a mistake to ascribed motives or purpose (Gnostic parable) to something and judge it according to how well it achieves that purpose (inferior execution) when it could be considered more successful by other plausible purposes.

I did not mean to give the impression that I judged The Truman Show or The Matrix solely based on how well they managed to convey the key principles of Gnosticism. I don't even know if their respective creators intended to convey anything about Gnosticism at all (not that it matters, really).

Still, Gnostic themes (as well Christian ones, obviously) do feature strongly in these movies; more so in The Truman Show than The Matrix. What I find interesting about The Truman Show is not merely the fact that it has some religious theme or other, but the fact that it portrays a person's intellectual and emotional journey of discovery and self-discovery, and does so (IMO) well. Sure, you could achieve this using some other setting, but the whole Gnostic set up works well because it maximizes Truman's cognitive dissonance. There's almost nothing that he can rely on -- not his senses, not his friends, and not even his own mind in some cases -- and he doesn't even have any convenient superpowers to fall back on. He isn't some Chosen One foretold in prophecy, he's just an ordinary guy. This creates a very real struggle which The Matrix lacks, especially toward the end.

The 'batteries' thing gets a bad rap but I can suspend my disbelief on that if I try.

AFAIK, in the original script the AIs were exploiting humans not for energy, but for the computing capacity in their brains. This was changed by the producers because viewers are morons .