So all this may be a hologram. Should this worry you? I don't think so - at least no more than the idea that everything may be composed of tiny vibrating cosmic strings or that all possibilities are actually played out, as in the many worlds interpretation.
The holographic universe idea does not equate to acceptance, tacit or otherwise, of the simulation argument. But the notion of us playing out an ancestor simulation isn't as laughable as it may appear.
To me it's an issue of resolution. How grainy is reality? Of what type of "pixels" is our universe composed? It seems logical that there must be a smallest unit of reality and that that unit may be fiercely insubstantial. But at the same time it feels counter-intuitive because we think of ourselves and our world as solid and not "projected" in the way that pixels are. If you can accept the idea of our being "projected" at any kind of resolution, albeit a mind-bogglingly high one, then you can accept that something might be running the projector.
None of this implies God. Any intelligence capable of running ancestor simulations must have itself evolved from something less intelligent. The very idea of such an intelligence wishing to run the simulations indicates that they are doing so in order to see how they themselves evolved. God never gets to evolve. How dull.
Enough of the wild speculation and back to holograms. We accept that a moving image on a 2-dimensional surface can give us the illusion of 3-dimensional reality. We will soon have to accept holographic "televisions" that sit in the centre of our rooms, so that we can walk around them and do such banal things as looking at the back of the actors heads while they recite their lines. It is a big leap from that point to accepting our universe as a holographic projection but would it make us any less "real" if it were true?
I am a thinking entity utilising synapses, neurons and glia. Beyond that functional level the units of the thinking substrate become markedly less tangible, but that doesn't affect my ability to think. I would like to know how small the units get because that is the kind of thing that brains ponder? But if I eventually come to discover that I am actually living in a kind of Flatland that won't invalidate me as a thinking entity.
Being part of an ancestor simulation wouldn't either.