Leave a record of what you have done, so the project will not miss you if you leave.
If change is the only constant, then resources on a project will change. The risk in such change is that a person’s contribution to a project will be lost, and that the new person assigned to the project will have to start over.
This is a particular risk in “quick and dirty” projects where an operating result is produced, but no one else can understand the code that was produced. However, if the contribution involves producing quality artifacts in my previous post, there is always a point-in-time record of what has been accomplished so far, which can be used by new project resources to continue the project with minimal disruption.