In the US, I think part of the reason why this is the case is because the cost of living goes up significantly more than the cost of living adjustments.

For example, while landlords aren't supposed to raise the rent by more than 2% per year, I've had my landlord surprise me with a 5% change, but moving is too expensive to realistically consider [1].

Factor in all the additional costs of living, and if you don't get significant raises every year, you're going to fall further behind each year and be unable to afford a family, a house, or an emergency.

It's not great.

1 - When I moved to a good neighborhood in NYC, I had to pay a brokers fee of 15% + moving costs + up front costs to the landlord. Say my rent was 3k, this would be 5400 (0.15 * 3000 * 12) + ~500 + 9000 (first + last + security), or approximately 15k just to move into a place you don't own.