Children who have tasks to do at home feel proud of themselves. They learn skills and feel competent. It is also good for their mental health. Start small with tasks that you think they can accomplish and then if you wish you can slowly increase the frequency or type of tasks.
While it may be more efficient to do these tasks yourself, helping your children feel useful and teaching them skills that they will need for the rest of their lives is a worth while good. It increases their self esteem, helps them feel competent and is therefore good for their mental health.