Since moving out of the Los Angeles area, Eva and Randy Fluker say they miss summer weekends at the beach, monthly trips to Disneyland and their favorite Mexican food and ramen joints.

They don’t miss trying to squeeze their work life, two stuck-at-home kids and Ms. Fluker’s 98-year-old grandmother into a 1,700 square-foot house in Norwalk, Calif. They joined a pandemic-era exodus of Californians to the Riverside-San Bernardino metropolitan area known as the Inland Empire, the biggest movement of people in the most populous state in America.