It is also related to the height of the mortgage rate; higher rates means more people cannot afford to buy a house, so house prices go down.
With the current unprecedented low interest rate levels it is hard to imagine, but there was a time that mortgage rates were above 10%. And there is no fundamental reason why they couldn't go back to those levels one day.
Sure, but real estate markets are local. At least in the US, there are plenty of places where real estate prices are not increasing, because local populations are not increasing, wages are not increasing, and wealthy foreign investors are not looking to park their money in places where real estate prices aren't going up quickly. So, yeah, in a broad, long-term statistical measure, re prices do tend to increase over time, but the distribution is far from consistent or uniform.
As a society, we should address this. I'm more a fan of spreading ourselves across the cosmos and stepping off the planet than say mandated controls here, but it is something we should be discussing. There is a point in time where there isn't enough world for all the people on the world to live a moral life. (and its odd we seem comfortable in many ways that "War" is this answer..)
Virtually everyone alive now is going to die on this planet, and their children, and their children's children. It's vaguely possible that someday we may find a place elsewhere for future generations to destroy eventually also, But no more than a tiny few are going to get to go; it will make no difference to the people left behind. We will have to continue to struggle on with what we have.
With the current unprecedented low interest rate levels it is hard to imagine, but there was a time that mortgage rates were above 10%. And there is no fundamental reason why they couldn't go back to those levels one day.