It is difficult to say exactly why God created this world/ Universe/ Us.
But perhaps He created this universe and us so that we could worship Him and offer oblations to Him, allowing Him to receive energy.
No matter how powerful God may be, perhaps there was no one who knew of His existence or greatness. Maybe that is why He created this universe and brought us into existence.
No matter how powerful someone is, if nobody knows about their power, what purpose does that power serve?
It is as though their power remains unrecognised and cannot be of any use to anyone..
(Disclaimer:- My intention is not to hurt anyone's sentiments)