For their conventional space launch operations they also want multiple... to target different orbits, and to parallelize the high volume operations they anticipate.
There's already two Starship launch sites. The one in use in Texas, and one (LC-39A) in development at Kennedy Space Center, Florida. And there's good reason to believe they've begun planning a third in Louisiana. https://forum.nasaspaceflight.com/index.php?topic=64900.0
On a more serious note, the Cape Canaveral area / Kennedy Space Center has a large amount of empty land to build space infrastructure. The island has been dedicated to space facilities since the 1960s. Both SpaceX and Blue Origin have facilities there.