There's nothing particularly natural about house prices always going up. I mean, you would expect property values to go up in high-demand locations, but the main driver of housing costs isn't that. There's two main drivers of housing costs:

1) Mortgages, which allow people to 'afford' more, which means that market prices rise to take that money from them; and

2) The fact that basically every municipal policy in basically every city in this country is dedicated to (this is a direct quote from a city I used to live in) "maintaining and increasing property values". "Property values" is the literal exact same thing as "housing costs". People who own houses vote for policies that make houses more expensive so that their paper wealth goes up. It doesn't have to be like this, it just is like this.