You need to understand the money that is driving these moves. Forbes ranks the value of each NFL team every year. By moving to LA, in one year the Rams went from # 28 with a value of $1.45B to # 6 with a value of $2.9B. The 49ers made a similar leap the previous year going from Candlestick to Levi's Stadium, a move of only 30 miles.
During that same year, the Colts dropped from # 14 ($1.88B) to # 18 ($2.2B). They will continue to drop every year as the Chargers will certainly leapfrog Indy this year.
https://www.forbes.com/nfl-valuations/list/#tab:overall
https://www.forbes.com/pictures/mlm45fljdi/nfl-team-values-2015/#22d179a878b7
During that same year, the Colts dropped from # 14 ($1.88B) to # 18 ($2.2B). They will continue to drop every year as the Chargers will certainly leapfrog Indy this year.
https://www.forbes.com/nfl-valuations/list/#tab:overall
https://www.forbes.com/pictures/mlm45fljdi/nfl-team-values-2015/#22d179a878b7