This has nothing to do with any strong form of the efficient markets hypothesis.
If there aren't jobs for the people in Berlin, then obviously they can't pay these great housing prices that the OP claims they can. I guess barring a case where Berlin is a vacation spot for the idle rich, but I don't think that anyone is arguing that.
If there are plenty of jobs, but housing is super-abundant, then I suppose you could make some weird case for there being a non-efficient market that's propping up housing prices despite there being no reason for that. And then landlords are, heh, making a rent, not the normal one but the economic concept, and sure, Berlin is super-overpriced for what it should be. But that's obviously nonsense too, everyone knows that Berlin is affordable.
I don't care if markets are for some reason inefficient the other direction and landlords are making less than what they ought to be -- the entire point of this ridiculous digression was the OP's claim that Campus could design an attractive model city which people would flock to despite there not being any jobs, and the point is that Campus is a landlord. They will not grow and become a giant disruptive force in the world if they are not making lots of money. If they build cities in which landlords for whatever reason make less money than they "ought to," then they will not grow and will not make many cities.
EDIT: I think this was all lost in the weeds, so let me play out the whole thing. I am not denying that Berlin is a vibrant, great, wonderful city that is also affordable and is attracting people for any reason you care to name. All I'm saying is that there are two possibilities:
1. Jobs are scarce in Berlin -> people do not have a lot of money in Berlin -> landlords do not make a lot of money in Berlin -> Campus could not make a neo-Berlin and then roll the incredible profits into making neo-neo-Berlin, because Campus is a landlord.
2. Jobs are not scarce in Berlin -> Berlin is not the counter-example that the OP thought it was.
For whatever it's worth, I think that the actual situation with Berlin is that it's still affordable but getting less so, and the OP confused the graph with the graph of the first differential.
EDIT2: In the case of Berlin, you could I suppose make the case that landlords are renting properties for low absolute rents but high profit margins, and that thus a sufficiently large landlord could use high volume to produce large absolute profits. But I don't think that could be the case for a new city. Building a city is a capital-intensive process -- even if the land is inherently cheap, building the structures and the infrastructure is just expensive, full stop.
What (may have) happened in Berlin is that somebody did the expensive city-building and then took a bath on it. Present landlords who are (hypothetically) making a good profit bought the distressed assets cheaply and now are making that profit off low absolute rents because essentially they've profited from the previous landlord's failure. Again, this is not a potential route to high absolute profits for Campus' potential future cities, as Campus will be the first landlord. They will need relatively high absolute rents in order to have substantially high absolute profits.