Why is the health bar displayed in the world?

Time travel may happen more than once.
The system that Li Mo got in exchange for sleeping for sixteen hours every day was incomplete. The moment the system started, a blood bar appeared in front of him in the world.
When he came to Demon Slayer, Tanjiro was five years old. He became a pillar that stood tall and firm, strangling tragedy in the cradle.
After coming to Genshin Impact, he became connected with the deceased priestess, and his life became connected with foxes.
Came to the Type-Moon world, and summoned a rabbit that was not a fox with the Witch of Betrayal, and learned its "Long Tail" method.
……
……
Survive, fight, evolve. Li Mo is walking on this road.
"As long as the health bar of a being is visible, I will kill it even if it is a god."