Life drawing art classes are not just for those who wish to draw the nude. They're a great way to learn vital drawing skills. These skills are very important to enable you to draw and paint in any medium and for whatever subject matter you prefer. Drawing is about being able to look and see clearly what is in front of you and being able to put it down on your paper or canvas.
Nothing reveals poor drawing skill better than life drawing art classes. If you draw some pots and pans, or a few flowers, or even a tree, you can make quite a few mistakes and your drawing will still look pretty good. But when you draw a naked human body even very small errors can ruin the sketch. We humans know ourselves too well and soon spot any mistakes!
Learning how to draw the naked body will enable you to draw anything you wish and will improve your paintings.