I am genuinely surprised that that combination is affordable in Berlin. Not like that is a small city or anything. How can you possibly find that much space at an affordable price?
But from having bought a place in a high demand area recently, the thing is always "who are you competing with". When the average person with 2 kids and a dog are looking at the same houses in the same places as the other family with 2 kids and a dog, there will be differences, but overall it won't be too bad. The problem start when that family wants the exact same house/condo/whatever as the 2 highly paid software engineer with no kids.
Then you're screwed: you're competing on a different level. And there's starting to be a lot of people with high dual income and no kid. The US is generally a nation of divide between the haves and the have nots, but the cultural divide is making things waaaaay worse.
Even in SF, the housing is a lot larger than almost all of Europe. London is a disaster if you expect much if any space.
I'm not sure why that is. Being physically cut off from the world helped keep prices down for sure, but it doesn't explain why apartments are large relative to the number of bedrooms.