Do you believe that one day it will be possible to make a simulation that is indistinguishable from reality?
No.
What about making videos with automatic voices that are indistinguishable from reality? If not now, what about in a century?
I think representations in a way are simulations. So a video of a real event is a simulation of the real event and a video of a fake event is a simulation of a representation or simulation of a simulation. So what you seem to be asking is since layman using ordinary senses through a computer interface have a hard time distinguishing between a simulation and a simulation of a simulation, wouldn't that imply your original thesis: one day it will be possible to make a simulation that is indistinguishable from reality.
Let me try to define some things here. First, a simulation to me is a representation of a thing in some way, it's a thing that mimics some features of another thing or category of things and in order to do that it is either incomplete as there are things that it does not possess, at a minimum it could be the true process or true location, or it is inconsistent with the real thing or category of things, meaning a feature(s) does not fit. Second, "distinguishable" to me means that it is logically possible for an appropriately trained or skilled person utilizing the right technology to ascertain such difference (incomplete mapping or inconsistent mapping) between thing A and thing B (or set of things C). Thirdly, I will now posit that the technology to create simulations cannot surpass the technology of the same era that is used to detect either the incompleteness or inconsistency between a simulation and a real thing. Though particular experts from time to time may have difficulties--perhaps not all information is available to them for example--it remains logically possible at all times to distinguish one from the other.
Now when you write about indistinguishability you seem to be using it in a less academic manner--like say socially by laymen and expert fraudsters. So, for example, suppose a hundred years from now a person is drugged and a future-technology VR head set is placed on them so that when they become semi-conscious they experience a simulated environment. They then behold themselves in the VR murdering a person and in the VR eventually they go to sleep while in reality they are drugged more to go unconscious. They wake up and some people dressed up as police take them to the station to question them and yell at them. Would they _believe_ they were in a real event? Probably.
To me, that is a very different thing from a blanket statement saying that a simulation is indistinguishable from reality.
Finally, I will just add that I don't think this idea of a simulation is new, except for the terminology makes it sound scifi. It really is more of a vestigial artifact of religion. The way religions function is to offer something to people and get something back (usually money, sex or power). The thing offered is unreality--usually the fake existence of something beyond life such as an afterlife or an enlightened state. There's no waking up and taking off the VR headset in another dimension when we die. When we die, we die. There's no interesting cool Matrix. There's just life while we are here.