First of all, and most simply, if this were the case, you could never know it, since your experiencing of coming to know it is also part of that matrix programming, and thus also illusion. If it is then an illusion, it cannot be true. It’s “truth” is also part of the hologram. Secondly, you would have no experience of non-hologram universe to compare it to to say that your experience is a hologram.
The claim “you’re at least experiencing something” cannot be a self-evident epistemic starting point like Descartes thinks. For one, it presupposes an “I” or personal subject as the ground of that experience. Yet we’ve claimed to only want to prove what is most basic – simply “I am experiencing.” Further, it presupposes linguistic philosophy which is ridiculously indepth. The sentence ‘I am experiencing” presupposes all kinds of realities which must obtain. E.g., that words have meaning; that words match up to conceptual realities; that there is a distinction between one and many, subject and predicate, etc. Further, it presupposes some kind of time-based experience. The list can go on, but what is obvious is that the original claim is not as simple and self-evident as prima facia supposed. In fact, it is infinitely complex.
If we wanted, we could even get into the complex semiotics and symbology of each letter of the sentence in the claim “I am experiencing.” There has to be some identity over time to these symbols that inhere. “I – A – M – E – X – P – E – R – I – E – N – C – I – N – G.” Some standard of diffrerentiation between each of the symbols is presupposed, as well as their mapping in a horizontal fashion, as well as their grouping into certain sets – I alone, A and M for AM describing a certain state of affairs that appear to be time bound, and so on. This can go on and on, but it should be obvious that the purported simple claim is irreducibly complex.
So, a presuppositional, phenomenological and symbolist analysis shows this to be impossible.