When I was young what used to happen is house prices would rise, and then reach a level were first time buyers could no longer afford the cheapest houses, and prices would then fall. This cycle of increasing and decreasing house prices meant that house prices stayed at a reasonable level.
And then banks and building societies created buy to let mortgages. These did not exist in the recent past. Suddenly people could become landlords without outright owning the house. And house prices began to rise and rise and rise.
Potential first time buyers could often no longer afford the cheapest houses.But prices did not fall as they used to, because the buy to let landlords were still buying the properties.