-----
After the twins had created their civilization and nourished it for thousands of years, they finally began to advance into the creation of space-faring technology of amazing heights, and their magic expertise also began to grow exponentially.
Although they could do most of the things they did, the goddesses suddenly found out outsmarted by their own people as they ended making all sorts of new inventions, they couldn't possibly make themselves, their own civilization had reached the breaking point where they were surpassing the two goddesses and becoming incredible.
Of course, they only felt joy at this. After all, it is the goal of any god that creates their own people and civilizations to reach a point where their own people begin to surpass them slowly but steadily! It is like the goal of a father to see his child one day become a better version of them, a better version of what they could had been, and an even stronger one too.
Check "The Protagnist's Sister Is Actually the Strongest"!