If a tree falls ...

Suppose a tree falls in the woods and nobody sees it fall. Has it really fallen?

Or suppose someone does see it fall but they drop dead before they can tell anyone about it.
Or suppose they don't drop dead straight away but they don't bother to tell anyone about it and they die many years later.
Or suppose they write about it in a secret diary which is later destroyed in a fire.
Or suppose the diary is not destroyed, but is never discovered.
Or suppose it is discovered many years later and nobody can decipher the writing.
Or suppose the writing is deciphered and celebrated as a holy text by a whole culture for many generations. But the culture is destroyed by a cataclysmic event which leaves to trace of it ever having existed.

When the Sun becomes a red dwarf and there are no humans left in the universe, will it all amount to nothing?

There was no flower until there was an eye to see it

"There was no flower until there was an eye to see it"

Charles Darwin

Or you could say 'There was no universe until there was a mind to perceive it' - or perhaps until there was a culture to understand it.
There were no dinosaurs until there was a science to understand them.
There were no atoms until we invented them.
There was no matter until we defined it into existence.

We created God and God created us.
The universe is sustained by our consciousness and creativity.

We are stardust.
We are the sons and daughters of the universe - we are of it and it is of us.
As the alchemists said "as above, so below"