With a payload volume of 8m diameter by 22m height you could fit a James Webb size telescope inside with minimal folding. The sunshield (21.2 m by 14.2m) would only need to fold along one axis and the mirror (6.6 m) could be monolithic instead of having to fold, probably only requiring the mounting points for the primary and secondary to be hinged. This shouldn't be discounted because it makes telescope design much simpler and less expensive.

It also allows for launching individual space station modules that have almost the same volume as the entire ISS in one launch.

Their plans for refuelling on orbit with tanker versions of the starship open up the entire solar system to unmanned missions with much shorter timelines and much higher payload size and weight.

The fact the entire system is re-usable will make it both cheaper and faster to use than any other launch system.

All of this combined mean that it won't just be countries and space programs bidding for space on launches, it puts space within reach of many corporations and some private individuals. This isn't conjecture, it's already happening with the Falcon 9. Starship will make it even more accessible.