I actually knew about the history of the NFL, and I have been following the NFL since Super Bowl 21. Not all owners of the NFL are Billionaires matter of fact.
Mark Davis of the Raiders is worth around 500 to 600 million dollars. My favorite NFL team, the Green Bay Packers doesn't have Billionaire owner matter of fact. The Green Bay Packers are Community owned professional Sports team that is owned by stockholders. Instead of an owner, the Green Bay Packers have a Team President.
You don't have all you fact straight on why the Raiders left the Market a first place. The NFL forced the Raiders to move back to Oakland and the late Raiders owner Al Davis sued the NFL for that. AL Davis lost the lawsuit and the Raiders don't have a Billionaire owner as a result. Yes, do I realize LA had attendance issues with the NFL in the 1990's.That market is football market for years, but it always been for College Football.
While all the teams you mentioned were in LA, the sports media wanted the NFL to go back to LA for a while even before the owners wanted to move. ESPN has people in the past that wanted the NFL to go back to LA for years because of the market. Other Sports media outside of ESPN mentioned in the past on wanting the NFL to go back to LA also. The true fact with the Sports media for whatever sports thinks every big market needs to have a sport in it.