When it comes to things like space telescopes, a cheap 100 tons to LEO would change the paradigm of how things are developed completely. When it comes to deep space missions that are a one way trip it’s not clear Starship does better than something like the SLS which was cost optimized (see big dumb booster)
The way Starship is being developed, with failure being very much an option, could get to LEO with cost optimizations. Mars is a different animal —- if takes 10 tries to stick a landing you’re going to wait 25 years.
The key problem of deep space colonization or exploitation is the long turnaround time. I did an unpublished study of the problem of turning asteroids into solar sails and concluded that it would be impossible if you disn’t have a physical twin in space near the Earth to teat anything (like fixes to problems) that needs testing. The problem of landing Starship without chopsticks could be tested exhaustively at White Sands, for instance.