Why is Rent in Tijuana, Rosarito and Ensenada Mexico so high?

Since the US reopening of the economy in Southern California, thousands of Southern California's and many from other places in the US, have chosen to move just south of San Diego to Tijuana, Baja California due to the high cost of rent in the United States. Because of this cost in Tijuana Mexico specifically it is hard to find a nice apartment or monthly Airbnb for less than $1000 a month, before it was easy to live in Mexico for $300 a month or less.