Dorei Kara no Kitai to Hyouka no Sei de Sakushu Dekinai no da ga

A boy named Allen is given the ability to heal any injury or illness by a goddess after being reincarnated. He purchases slaves and intends to use his skill to restore them while living a quiet life. However, the slaves' abilities prove to be unexpectedly powerful, rapidly improving their work and living conditions. As the slaves excel in all tasks, Allen finds fewer chances to contribute. He attempts to use his modern knowledge to regain relevance, but the slaves quickly absorb and apply his ideas, leading to continued success without him. Over time, Allen becomes increasingly unnecessary.