A large part of the price in indeed related to offer vs demand but that's the basics for any market.
Now it's funny because you also say "Estate agents charge more because people will pay it because anyone who can’t afford it goes homeless [...]".
So it isn't just offer and demand isn't it?
When you think about it, even in areas like London the housing market is not liquid nor uniform enough for the offer vs demand model to apply. You don't rent/buy home like you buy strawberries.
In about 1 year there was no significant increase in demand and the supply stayed the same but everybody saw its rent increase.
Edit: Also we should not mix-things up, the housing market is very different in outliers like London compared to the more global market. Here we're in the context of those outliers (Paris, London, etc.)
When you think about it, even in areas like London the housing market is not liquid nor uniform enough for the offer vs demand model to apply. You don't rent/buy home like you buy strawberries.
In about 1 year there was no significant increase in demand and the supply stayed the same but everybody saw its rent increase.
Edit: Also we should not mix-things up, the housing market is very different in outliers like London compared to the more global market. Here we're in the context of those outliers (Paris, London, etc.)