This New York Times article discusses some of the changes that might be needed to prevent the common problems associated with growing older.
I don’t think we have to wait until we are 50+ to wish for design changes, do we? I’d wish for more uniformity in packaging, something like all females 5’6" tall and all males 5’9" tall. Clothing, housing, car manuf. all be simplified and we’d probably learn more about feeding ourselves without wasting extra food on extra large bodies.