@AbbeysDad has covered it pretty well.
You can reduce the frequency of water changes if you only have a small number of fish in the tank, and only add a small amount of food, and you have lots of live plants that are growing well, and you manage the pH, GH and KH of the water. However, if you have a lot of fish or put lots of food in the tank, or don't have many live plants, or let the pH, GH or KH change dramatically, the fish will suffer.
If you are doing weekly water changes, perhaps do them every fortnight instead. Reduce the food going in and get some floating plants if you don't already have some. Do a 75% water change and gravel clean the substrate every 2 weeks and see if that gives you more time to spend with the family or doing other things.