The traditional materials used in Japanese construction of everyday homes aren't really in the "built to last" category: https://www.youtube.com/watch?v=i1DP5xpM3Y8 . In some cases, trying to make a house that was resistant to floods, fires and earthquakes at the same time would have been prohibitively expensive. I'm sure that led to forming habits that have continued into more modern eras of building styles where it's less required.

They're also smaller, which makes construction costs cheaper which means people are more likely to make dramatic changes when fashion changes. And then there's more of a culture of prefab house building rather than extensions etc. Planning is also a lot more liberal which allows the rebuilt house to be more different and also reduces the cost of the process.

I think even in Europe some of the older houses are houses of theseus though. The exterior shell is the same, but there's plenty of buildings in the local city centre that were tenements, then small business offices, then apartments, with significant remodeling that occurred. Or the house I used to live in was built in the 1880s, extended in the 1950s and significantly modernised in the 2000s. Each time there would have involved largely gutting the interior and rebuilding.

Interesting, thanks! The regulatory explanation makes a lot of sense- I once tried to pull a permit to install a ceiling fan in a small USA town, and it was a nightmare.