After the Space Shuttle, a full-envelope launch abort system has been a hard requirement of NASA for human flight. SpaceX's Crew Dragon has such a system; if SpaceX wants to fly NASA astronauts on Starship they'll have to add one.
No full-envelope abort system exists or likely will exist for human lander ascent systems. That breaks the "hard requirement" argument if we're going to the Moon or Mars.
Right now, sure. If we use this low cost space access to build a Moonbase equivalent to the ISS, it would be good to be able to return back to that base of the launch failed.
I won’t be surprised if there is a better solution than a launch escape system, perhaps like a non-rocket launch in the form of a lunar maglev launch track, but it’s probably worth figuring out soon-ish.
I don't see anything about the Starship design that would prevent a future version with the nose cone being sealed off with a bulkhead, along with and explosive bolts attachment mechanism and Super Dracos attached (plus parachutes). The mass budget is there, and if it is designed to be detachable only in emergency then it could be a lot simpler than a separate capsule system design.
