Holy Lands were places with rich and dense heaven and earth energy, even if the energy was elemental in nature. They appeared and fell continuously until it was no longer required since the supply outweighed the demand in terms of livable energy requirement, with the longstanding peace of the human galaxy.
Huge battles didn't break the curvature of the harmony between heaven and earth because they weren't fought frequently in front of the common populace anymore. After all, the energy of Exalts and Primarchs would cause heaven and earth energy to recede for a period of time since the latter would be busy repairing the damage and clearing the remnant energy they left behind.
