Feb 28 (Reuters) - HP Inc HPQ.N on Tuesday reported the steepest fall in quarterly revenue since 2016 and missed analysts' estimates, hit by delayed computer and printer upgrades by customers in the face of high inflation and economic uncertainty. Rising costs, tepid consumer spending and recessionary fears have pummeled several sectors across major markets including the United States, with computers and peripherals taking one of the worst hits in retail categories. The company also said 900 employees in the United States were taking voluntary retirement as part of its previously announced plan to reduce 4,000 to 6,000 jobs.