It does not do to dwell on dreams and forget to live.

In Kakashi's dream world, he was never born.

Hatake Sakumo does not end his own life after his failed mission thanks to the support and counsel of his wife.

Uchiha Obito does not lose an eye or himself to the darkness. He urges his clan to work with the village instead of against it.

Uchiha Sasuke does not grow up bitter and brittle. He dreams of surpassing his brother, not killing him.

Haruno Sakura does not sideline herself and rebuilds her self-esteem under the tutelage of a different sensei, one who refuses to sideline her or leave her issues alone. She is later apprenticed to Nohara Rin.

Konoha's jinchuuriki does not die on her son's birthday. The Fourth Hokage reigns for decades.

In Kakashi's dream world, he was never born.

(He wants to sleep forever.)

Note: Written before 678, so this isn't based on a canon understanding of the Infinite Tsukuyomi.