Why gold is your wall-and-defense currency
On your Home Village, gold does one job above all others: it pays for defense. Every wall segment, cannon, archer tower, mortar, Inferno Tower and Eagle Artillery is bought and upgraded with gold, and so are your gold storages and much of the Town Hall itself. That makes gold the resource that decides how hard your base is to three-star — the exact opposite of elixir, which funds your offense. If your walls and defenses are lagging behind your Town Hall, a gold shortage is almost always the reason. This service fills your gold storages so those defensive upgrades never stall waiting on loot.