I like what the CCC says about why God made us.
God, infinitely perfect and blessed in himself, in a plan of sheer goodness freely created man to make him share in his own blessed life. For this reason, at every time and in every place, God draws close to man. He calls man to seek him, to know him, to love him with all his strength. (CCC §1)
God is infinitely perfect and blessed in Himself. There is no defect in Him that compelled Him to make us. There was no obligation to do so, either (which should be obvious): He can’t owe anything to things which don’t exist! There was no need for Him to create, but out of sheer goodness He chose to do so. How then ought we to live, who exist just because God was so good as to create us? We ought to gratefully love Him. And since He made us for a reason, we ought to freely and thankfully seek to fulfill that purpose which is nothing else than to see His face.
Now that’s not the whole story of human existence: our lives in this world definitely matter, and are not irrelevant to our End, because God does nothing in vain. He would not have made us in this world nor given us these lives for no purpose, and that purpose is necessarily connected to achieving our End even if we can’t see it. So we need to do our best to love Him, and to love our neighbor for His sake because that is what he has called us to do in this life for the sake of attaining our End of seeing His face: “if you love Me you will keep My commandments” (John 14:15).