Did we? If we're in a simulation instead of base reality, it's possible that simulation have actually created them for us when we started looking, depending on the scope and paramaters of simulaiton scenario.
It's like asking someone on a date: maybe they were in a superposition before, but now they have to answer, and having answered ("been observed"), that answer is highly likely to stay constant in the short term.
(when you think about it from this point of view, it's classical physics that's counterintuitive: why should we expect that asking questions about one projection of state doesn't affect the answers we get from later asking about others, not even in the slightest?)
Does that make sense?
Just in the same way as that only visible from current perspective objects are being drawn on a frame of a 3D game.
Currently unobserved parts of the simulation might exist in different form.
It's okay to disagree with simulation theory, but it is a perfectly valid possibility according to everything we know.
Personally, I don't think it's the only possibility, but i think it's quite probable and should be taken seriously.
* if yes, then I'd have to admit that the omega-tower could be as interesting to study as the 0-tower, but if no then I'd maintain the 0-tower is way more interesting than any of its successor towers.
(this line of approach, less formal and perhaps more congenial to CPS' other culture, is inspired by Dewey and James' pragmatism, in which philosophical problems are only well-posed if they have "cash value". We hackers don't make comparisons without subsequently using the flag value; they didn't ask questions whose answers are moot)
If I were building a simulation I would just have not made gravity universally coupling because it makes it hard to chunk reality up into parts. Thus it seems like the universal coupling of gravity is evidence against a simulation hypothesis.