Is earning considered lawful or unlawful if a large wage is received for work in which little effort is exerted, knowing that the work is unaffected and its outcome is excellent?

The essence of your work lies in performing the task assigned to you as required. There is no objection if the work is completed by a team under your supervision and oversight, as long as there is no negligence. Be keen on developing the work, perfecting it, and ensuring its quality, while adhering to the terms of the contract; as Allah Almighty says: "O you who have believed, fulfill [all] contracts," and the Prophet, peace and blessings be upon him, said: "Indeed, Allah loves that when one of you performs a work, he perfects it."