For many, the standard of living is simply too high. There have to be great photos from Asia, etc. 2-3 times a year. Then cost drivers are technology. Internet, mobile phones, computers, tablets, consoles, etc. Many between 20-35 have all of that or at least a few. Additionally, cars cost more due to technology, and many lease a car for 200-400€ monthly instead of buying a decent car for 6000€-7000€ that would last another 10 years.
Then there are some gap years abroad and years for relaxation.
All of this was not so extreme in the past. Then it continues with the house. Energy standards that drive up the price, etc.
I see the consumption behavior as more of a problem than the prices. Sure, maybe luck and connections also play a role, but equally discipline. I myself wasted my money endlessly after training. Immediately got a new car and so on. You only live once, after all. But when it came to homeownership, compromises had to be made.
If children are to come, then one must save again beforehand and live off the savings for 1-2 years until the partner goes full-time again.
If interest rates should rise again at some point, prices will fall and in the end, one will still be paying a rate between 25%-40% of income.
Many also say that money is more sensibly invested elsewhere... Maybe so, but how many have any idea about the stock market or similar? I, for example, have absolutely none. I also see our house as an investment... If I pay 200-400€ less rent, then I wouldn’t invest that money elsewhere to multiply it, but rather get myself a nicer car or book a more expensive vacation. As it is now, "I just save less," but I save.