But you agree that a significantly bigger wall could explain the Fermi paradox in theory?

It's certainly a way to have a universe full of dark megastructures efficiently harvesting energy on behalf of ancient superintelligences, coexisting with a planet of yokels who just see a wilderness of stars squandering their radiative output. But I would rate 1. Great Filter 2. the "wilderness" is actually alive and busy but the yokels don't know how to see it that way 3. appearances are even more thoroughly illusory than in the planetarium scenario, all as more likely.

I figured you might be partial to naive realism.

That would make hallucination impossible. I think we have direct awareness of something, but not the outside world. The "something" is either part of us or it's alongside "us" in the brain.