WASHINGTON—The United States Postal Service (USPS) on Wednesday reported a net loss of $4.9 billion for the year ending Sept. 30, narrowing its losses over the prior year. USPS’s operating revenue was $77 billion for the 2021 budget year, an increase of $3.9 billion, or 5.3 percent. It reported a 2020 net loss of $9.2 billion. Postmaster Louis DeJoy in March announced a plan to cut $160 billion in predicted losses over the next decade. “We have years of inflicted damage to fix that will necessitate us taking some continued uncomfortable actions,” DeJoy said on Wednesday. USPS said shipping and packages revenue increased by $3.5 billion in 2021, or 12.2 percent, largely driven by the surge in e-commerce resulting from record holiday volume. First-class mail volumes fell to 50.7 billion pieces in 2021, the lowest number since 1971, and is down 51 percent since 2001. USPS has struggled with poor …