This always blows my mind. Our last house was 85 square metres and our current is 95. With a small child we need a little more, but any more than 120 is just too big. Too much crap accumulates, too much cleaning, too much maintenance (I could prep and paint the whole interior of our house in 2-3 coats in a week after work in pretty sure). Property taxes cost more with bigger houses and things get complex fast. For example, all water in and water out happens over about 7m of one side of the house. Leaks, supply etc are so much easier to deal with. I can get above and below any problem fairly easily as it's single level. When the child goes feral at night, it sure would be nice to have 10 doors between us, but no house could stop that noise. Medium/small house believer.
Those were the lot sizes, houses in the US/Canada are typically a little larger than those in Europe. Property taxes in the US/Canada are a small fraction of those in Europe.