I’m only an occasional football/sports follower, but my memory is that the Rams were in LA, and moved because despite the city’s population, it couldn’t sustain a profitable franchise? Was the stadium never sold out? Fuzzy memory.
When Dan Reeves moved the Rams from Cleveland to Los Angeles, they were very popular, and drew over 80,000 fans pretty regularly. When he died, Carroll Rosenblum took over, and the Rams remained popular, with stars like Roman Gabriel, Deacon Jones, Merlin Olsen, and Rosey Grier. They also liked the fact that being in LA got them chances at being on television.
When Carroll Rosenblum died, his wife, Georgia Frontiere (married six times, and one domestic partner) took over the team. Over the seasons, interest in the team declined, and they were drawing less than 45,000 fans per game when she worked out a sweetheart deal to move the team to her old home town of St. Louis. This was after the Cardinals split for Phoenix.
Part of the problem was that LA wouldn't pay for luxury boxes and upgrades to the LA Coliseum. Also, her husband got caught scalping Super Bowl tickets and did time. She was about as popular in LA as Bud Adams was in Houston.