McDonald’s Corp (MCD.N) plans to raise the average pay of about 90,000 U.S. workers to around $10 an hour, but the increase will not benefit workers at the vast majority of the restaurants, because they are operated by franchisees, who make their own wage decisions. Workers groups said the move by McDonald’s, which is also adding benefits such as paid vacations, fell short of their goals. McDonald’s, which announced the increases on Wednesday, has been fighting weak traffic and slumping sales in the United States.