Morality is objective
"If no set of moral ideas were truer or better than any other, there would be no sense in preferring civilised morality to savage morality." C. S. Lewis
Think about it.
If morality was not objective, we would have no firm basis for believing what we do believe, and therefore, no firm beliefs at all.
And maybe that is an actual issue today for many young people with no organic life experience, particularly in the West.
Perhaps our moral framework as a collective has holes in it.
Objectively, we can all agree that:
murder is wrong
stealing is wrong
lying is wrong
adultery is wrong
and so on...
What happens when we start believing that morality is subjective?
We allow justification for moral failings.
Murder becomes appropriate in certain circumstances (e.g. he deserved it)
stealing is appropriate in certain circumstances
lying to an 'enemy' is appropriate in certain circumstances
cheating may become justified
and so forth.
All this to say, morals that are subjective are another facet of a society that is slowly degrading.
It is apparent that we know intrinsically (most of us do, anyway) what is right or wrong as children. We may react negatively to another kid being hurt by a much larger kid (mistreatment) for example.
So why then, do we have such a hard time finding out what is right or wrong as a society? Because, without any explicit guidance from a higher power, man is left to his own demise. Especially now, in the West, where we are constantly bombarded with things that may lead us astray. Murder for example, is never justifiable.
Murder by definition being, to kill someone premeditated and with malice in your heart.
Simply put, morals are not subjective. And what is packaged as new and right now is misguidance and the adultery of old morals.
C.S. Lewis explains this more in detail in Mere Christianity. You can read more about what C.S. Lewis thought of Moral Objectivity specifically here