same thing, they take too long to start working. without active sensors/valves, they are useless for seismic and no one yet has been whiling to take the risk on active system. I'm sure we'll see them eventually, it's just not worth the risk for now.

In the article I linked, a paper is discussed "‘Earthquake response of ancient five-story pagoda structure of Horyu-Ji temple in Japan‘"

They vaguely list it as a contribution but they have nothing to back it up.

On the other hand, you have scientists who ran computer simulations and shaking table experiments proving that passive damper do almost nothing during a seismic event.

As I said before, the reason they rarely get mentioned by actual engineers/scientist in this domain who can back up their claims is that we've known for decades that they are literally useless for seismic. We're at the point where you don't even need to quote sources on your peer-reviewed article to say in your intro that they don't work for this use case.