Lightweighting benefits and considerations

With today’s driver requirements, such as electronic data loggers, some customers who traditionally use trucks with a 10,000-pound or greater GVWR are considering downsizing to vehicles less than 10,000 pounds GVWR while carrying a similar payload to the higher GVWR truck. We have heard lightweighting may be a way to maintain payload while reducing GVWR. Can you explain benefits and concerns associated with this approach?