You said;
"Because all of them are constructs of humans who found it necessary to somehow explain a reason for their existence"
And I asked for your reason for existence and you explained to me and everyone reading, that you're the result of an animal act
That may explain HOW you got here, but does not explain the REASON FOR YOUR EXISTENCE
You've already determined we whom are believers in God have OUR "reason" (you don't agree but it is not germane to "my point" ) which, if left alone, is one sided at best.
Why are you here ?
I was born a human as a result of a sexual act by two other humans.
Why are you here?