It’s not an “illusion.”Your preconceptions are wrong. It’s only an illusion if you think what you are looking at should be interpreted to mean what false science says it should.
Tell me, when we see a supernova exploding in a distant galaxy, millions or even billions of light years away, did the star whose dying light we are seeing ever exist?
I’ll second Buggman’s retort.
When I look through a huge ultra sensitive telescope at an exploding star in another galaxy in another supercluster, there are things I can _KNOW_ about what I’m looking at: it’s moving away at a certain speed (incandescent light from certain elements emit at specific frequencies which red-shift very precisely at certain departure speeds), I can count the number of stars between here and there and compute the minimum possible distance (any closer and gravity will cause collapse, but instead distances are expanding), and apply a host of other basic scientific principles I’ve learned by actually looking at what exists and doing things with it and watching what happens.
It’s not about “false science”, it’s about “real science”: there are basic principles of physics which can be directly measure and quantify behaviors, and when when used to predict other behaviors proves accurate at all scales to a vanishingly small margin of error (which invariably doesn’t mean physics is “wrong”, it means there’s more to understand - but never anything which totally trashes the model).
The reverse must be applied as well: if you assert that the universe is “young” (say, 10,000 years old) then that limits how you can explain certain realities, leading to physical & philosophical & theological absurdities (like “then stars must be only a few feet wide” or “God went through a lot of effort to make things look like what they’re not” or “that star is a billion light years away but at creation God had to make an enormous number of photons that look & behave like they _had_ travelled from that star for 999,990,000 years already”). At some point you may find yourself screaming “it’s a lie!” at everything you see - to wit: you are calling the universe a lie, and thus God a liar.
So, all that said...
Tonight, let’s both look up at the stars. How should I interpret what I see? and what I see is orders of magnitude of orders of magnitude of bright distant lights, a view which shifts in accordance with my position on the 4000 mile radius Earth which is revolving thru a 94,000,000 mile radius around the Sun, from which between angular changes I can compute that various stars are at a distance (confirmed by redshift) of dozens to billions of light years away ... that’s not “interpreted as false science says I should”, it’s just simple observations of what is. From there I can then ask “how SHOULD I interpret what I see?”, and seems my choice is between “God created those photons to behave as though they came from much farther distances than they really did” and “God created the stars up to billions of light years apart, with motions indicating He actually created them thru a process something like _______” ... it’s got to be, basically, one or the other - which is it?