That is because 'the end' will come not because of a preselected date, but because of the 'condition' of man.
And when it happens, no one will really even notice it happened, at first. It is likely it may have already occurred.
As far as the 'rapture', we might not really notice that either. How many true believers are there left?
How many people die or disappear each day on an ongoing basis?
You are correct in pondering if it will even be noticed by those left behind. The great falling away from God, the death & persecution of millions for their testimony...much is outlined in Revelations about the end of days. We're very far from it.
Will the coming of Christ be noticed and the rapture? According to the Bible it will be unmistakable, but much death & sadness comes first to the Christians.