Casdon House prices will always rise to the point where essentally all houses available for sale will sell. Any higher and lots of houses will be on sale but not selling.
House prices now are high because interest rates are low. At the moment house prices are falling for a combination of reasons, but the main reason is because interst rates are going up.
Yes, in the past multiples of incomes, especially second comes were lower, but there is nothing to stop lenders returning to one income only, and if they did, house prices would tumble, so that we got back to the equilibrium of the number of buyers and sellers being roughly equal.
Buying your first home and paying for it for the firsst 5 years has always been a struggle. I can remember when couples would be engaged for 4 or 5 years while they struggled to save enough to have a deposit on a house.