It's a speculative, blue-sky idea—as is the context discussion that's proposing to assemble space satellites in a remote desert for optimization reasons.
It's not technically implausible. Starship (upper-stage only) in principle has a very long hop range—it's almost an SSTO by itself [0]. In principle it could also support landing on non-spaceport facilities like deserts—after all it's explicitly designed for landing on the moon, in accordance with the NASA Artemis contract. Would SpaceX be thinking about trying long-range hops on Earth, as a testing mechanism? I'm not sure it'd be completely crazy to consider that.
Musk has extensively talked about the concept of Starship (full stack) as city-to-city passenger transport [1].
It's not technically implausible. Starship (upper-stage only) in principle has a very long hop range—it's almost an SSTO by itself [0]. In principle it could also support landing on non-spaceport facilities like deserts—after all it's explicitly designed for landing on the moon, in accordance with the NASA Artemis contract. Would SpaceX be thinking about trying long-range hops on Earth, as a testing mechanism? I'm not sure it'd be completely crazy to consider that.
Musk has extensively talked about the concept of Starship (full stack) as city-to-city passenger transport [1].
[0] https://en.wikipedia.org/wiki/Single-stage-to-orbit#Starship
[1] https://www.theverge.com/2017/9/29/16383048/elon-musk-spacex...