I believe the OP is not asking about materialism. Setting kasina aside and addressing the broader question: No, it doesn't matter whether the object of the senses is manmade or not. For example, a member of the opposite sex is not artificial while a fancy car or phone is. Lust can form for both. Likewise, we can easily find examples of when the both natural and artificial objects can trigger aversion.
Regarding meditation, in reality, the objects of meditation are really only 6, the six sense doors. Everything we know is known by the mind at these 6. The kind of objects you are talking about are objects of these sense doors. With some practice, they don't really matter. What matters is the reactions on sense doors and the feeling tones generated in the mind as a result.
The seclusion that the Buddha talked about was really seclusion of the senses. Yes, he did recommend going to an empty house, the root of a tree etc, but this was the aid seclusion of the senses. Notice that he did *not ask anyone to go to a place of natural beauty or look for beautiful natural things. This is one of the most common misconceptions about meditation - that you need a quiet, beautiful place.
The path is for practice wherever we are. There is some value to allowing somewhat favorable conditions, but this is not the first order endeavor.