Given our experience it is a reasonable assumption that things “exist”, and they exist whether perceived or not.
For example, the bottle of milk in my refrigerator remains there inside after the door is closed. There is no miraculous disappearance and reappearance between the closing and reopening of the door. More dramatic still is the piece of paper in front one’s eyes. The reverse side not seen directly does not cease to exist because it cannot be seen.
My point is reality has a characteristic, and we have learnt from experience of it. I function daily within this reality. I do not question it anew as that would keep me in a state of paranoia. I have decided to trust that this is its characteristic and live by it.
I have lived before without a trust of it. But I had been unhappy. It was a time of nervousness, of not knowing what would happen. A life where I did not know how to predict how things worked and how people reacted. It is still quite possible for people to behave differently than to what I would expect but I have learnt to expect variation and inconsistencies between reality and my expectations. The inconsistencies are just less than what they were before.
I would think Roger Federer when he plays tennis he knows and understands how the ball and opponent react to his strokes, so as to be able to win the tennis match. We can see he has trouble against Rafael Nadal who has better knowledge and understanding of the characteristics of the game on clay court. Their realities are not different. It is not a mental thing. It is a physical one. One translates the understanding to a physical one. One cannot tennis by mere thought. One has to play the game.
I will say this again in different terms – to be is not dependent on perception.
Berkeley resorted to God for his ontology. I say neither God nor perception (human or otherwise) is necessary. There is a fear that nothing makes sense without a posited Perceiver (God) or perceiver (human). This comes down to a misunderstanding of what (a poor word for a non-thing (about to be explained here)) is, for example, God, mind, perception or conceptualisation. These are not things but processes of things. Let me illustrate.
To run (to move very quickly, by moving legs more quickly than when you walk) is something certain kinds of things do. Animals do it. We do it. To run is not the animal as such but the process of the animal. But running becomes a thing when converted into a noun. Verbally we consider them things but this is a conceptualisation. The act of conceptualisation (like running) is also a process of a thing. Part of the problem then is to mis-take the nominalisation of a process for a thing when it is a thing only in name, not in reality. I extend this to mind (as processes of thinking, perceiving, conceptualisation) also as well as God (the process of conceptualisation and projection into a being).
I understand the last is especially uncomfortable for many people. It goes to the heart of one’s beliefs. But I have come to this conclusion, no more no less than from your own conclusions, from my faculties of senses and mind.
Much of the problem seems to me stem from the inability to see the difference between the logic of reality and the logic of language. The mind is not a thing. perception is not a thing. They are only made to resemble things because they undergo an act of nominalisation (a process in itself).