JRB has never been shy about saying he writes musicals primarily so that he can have a big Broadway hit (which continues to elude him), while Guettel has never had to say what everyone can see, which is that he could never work a day in his life and still live quite comfortably. But of the two, Guettel is the one who has had a Broadway show run for a little more than a year.
And you might be surprised, but I would wager that the bulk of Brown’s royalties are coming from “Last Five Years”. That’s the one that gets performed at every college (and became a movie), and I don’t think any of the commercial Broadway dreck he’s written comes remotely close. The other big source for his royalties is likely (and he’s written about this) individual songs like “Stars and the Moon”.
The weird thing is that I think Brown has incredible talent, and by all rights should have been a major Broadway composer instead of a dude who does mostly short-running movie adaptations that sound like he wrote them for the money. The main reason I’m so sore on him - aside from he’s just a miserable person - is that it feels like he’s squandering his immense gifts on generic musicals and the occasional flawed gem.