Dryer balls remove wrinkles from the clothes, and separate the clothes, allowing more air to circulate, reducing drying time, plus, if you want to add a scent to your clothes, you can add a few drops of essential oils to the dryer balls, and that way, you are not adding any synthetic scents to the process.
I have 5 of them felting in the washing machine right now, and I hope they turn out well. I'll update when they're done!