Life is a competition against your peers. It’s always been that way since you were in kindergarten. That is why they give out grades and scores in all types of events. Everything has a recognition of a hierarchy. Some will play first string on the team while many others don’t even make the team. College acceptance rates are low and good employment opportunities are even lower.
People are used to having a win or lose opportunity to keep their tasks more exciting to perform. Boredom will lead to regression. Create a culture between you and your immediate employees where you outline the expectations of tasks for them to achieve in a short term. Do incremental rewards as most people don’t have patience to wait.
If a crew of 3 supposedly is building your deck in 20 days, tell them if they get done in 17 days then you will buy them and their spouses dinner. If they get it done in 18 or 19 days, then just buy the three workers lunch next week. This way they have positive pressure from their spouses and do their best but at the end still feel like they win something. The reality is you win by saving a day of wages and overhead and you gain the management aspect of a crew.