There are tons of possibilities; James Web 2 with 10x the diameter, a probe to catch up with Oumaumau, real asteroid prospecting. Oh and orbital hotels. Does anyone know of any concrete projects?
There is currently probably an almost infinite market of sending middle class people into space to experience true microgravity and LEO, and if that's viable then you're already setting up a secondary market of people who would want more (3 days to orbit moon? At say...$30,000 I'd do it).
Space tourism gets oversold a lot, but in a scenario where prices are accessible to the middle class and you make a little money...it would be a long time before you'd run out of customers.
But I guess 10 thousand people out of the 8 billion that currently inhabit the Earth would be willing to spend 30 thousand bucks to visit the Moon. Getting all of them there and back would actually mean quite a lot of effort.
First, in revenue, that's $300MM. A lot of money, but doesn't seem to be a lot of money for the costs of running that number of Starships, let alone the building of them or R&D.
Second, if we assume 1% of people want to go into space, the 10,000 people would be out of the richest million people on earth. That is not the middle class. In fact, those million people will have more wealth than the entire world's middle class.
Oh, and don't forget the contract from NASA for landing humans on the moon.
IDK how many engineers qualified in designing space-resistant hardware are out there, but I am almost certain that many more will be needed. Space conditions are pretty brutal on components.