The mystic perspective is that we’re all one thing. That means that you and I and all other things are part of God.
In a sense, we do the experiencing on God’s behalf as God has the awareness of all things (omnipotence). We’re all small pieces of a much larger body.
All realities contain matter (including dream realities), all matter must be observed by a mind as matter cannot observe itself (even when we dream). Matter is limited, mind it seems, is not. Thus all realities including dream realities are real to the dreamer, the dream itself may be the basis of all reality. God may be a dreaming god.
These realities are inconsistent when we dream, but God being the greatest mind of all, probably could maintain a consistent dream world if he/she/it so desired.
The other possibility is that reality is made whole by our overlapping awarenesses, in a sense each person creates a bubble of reality that overlaps with all others to create a consistent whole. Each person that is removed from such a worldview (by death etc) would make us all poorer, diminishing reality, every new arrival (births) would make us all correspondingly richer.
It’s interesting to muse, as we have no idea how consciousness really works, it’s not as simple as saying that it arises as a product of the human brain, that firing synapses and the excreting of neurotransmitters is the basis of consciousness. The chemical soup model of consciousness doesn’t do it for me, but matter being observed by mind does make more intuitive sense at least for me.
There’s an old occult saying that nothing in the world is actually real, only the originating thought is real. In other words, a man could build a grand building full of columns and portico and all sorts of beautiful adornments.
He’d have to take raw matter and shape it into bricks and pillars, make arches and doorways, all of which would eventually crumble into ruination and dust, however the originating thought or idea that propelled the construction would remain unchanged. Hence only the thought is permanent, only the thought is real.