A huge synthetic telescope in orbit with an aperture the size of the planet?
How many private earth observation satellites?
The market is huge when weight constraints largely go away and $/kg drops so hard.
What does that even mean? Almost every single Falcon 9 customer will prefer launching on Starship if/when it is available, because the cost will be much lower. A very small segment who have payloads that are exactly Falcon 9 sized and want a very particular orbit might still be better served by F9, but maybe not.
Beyond that, much lower cost unlocks previously untenable opportunities that you have not sufficiently imagined, as stated earlier.
(I'd like it to be, but until it is, it isn't).
Cost reduction depends on it being fully reusable.
I'm only saying your previous "will be" is too strong a claim, not that it's completely unthinkable that it may come to be.
That said, it's not like other billionaires aren't working on the same basic idea, even if they're copying what was already proven with the Falcon 9, which is great for people who want to go to space but not so much for SpaceX investors.