Brick/stone/adobe are not insulators. They have substantial thermal mass, which means that they act to stabilize temperature. Put differently, they create a phase delay between exterior and interior temperatures changes.

The problem with this model is that it works in both ways if you live in a climate (like much of the USA) with substantial swings in typical daily temperatures between seasons.

The same massively thick stone wall that keeps the medieval castle cool in the heat of summer is also chilled to well below freezing by the deep cold of winter, and turns the castle (or whatever) into an icebox.

This is why sensible construction involves both thermal mass (stone/brick/adobe) and insulation. The former helps stabilize temperature, the latter prevents substantial gradients between the structure and the interior (or exterior) from causing major energy flow.

It's not that wood is super-insulating (though it's certainly better than stone). It's that wooden beams are spread far apart, and the space between them can be chock-full of insulation.

And as another commenter pointed out, the main reason isn't summertime insulation -- it's wintertime insulation. Stone is freezing. When it's -20°C out, insulation in between wooden beams makes all the difference.

Concrete blocks filled with insulation still just have way too much concrete to transmit the cold directly from outside to inside.

Aerated concrete for walls is a very awesome idea from Europe, but it’s not structural and by the time you build the structure for a typical two storey I’d bet that stick framing would be cheaper.

Euros typically put a much higher ratio of their income into housing and are willing to spend more. Same for Japan, and they build very good houses, but then tear them down after a couple of generations.