>>12686565We'll never know unless we can find a way to get some long term seismometers working on Venus and that doesn't seem likely any time soon. Even if the heat and pressure issues are solved that planet resurfaces and is fairly geologically active, so your seismometers are going to get weathered away pretty quick.
But I suspect it's a combination of:
Venus fuckes up rotation, it probably doesnt have as a big a core as Earth because Earth likely ate and consumed a Mars size proto planet (which is why Earth has a massive core), and the fact that Venus doesnt have a large moon tidally heating the planet.
I suspect in general most terrestrial planets die off in 4-5 billion years simply from their cores going solid. Earth is an absolute outlier in our own system for still being geologically active and warm (and not an ice ball sub surface ocean tidally heated moon).
It's actually my preferred "great filter" for the Fermi paradox. I suspect that the overwhelming majority of planets, even those in the habitable zone, are only fit for life for an extremly short period, far too short for the development of complex life, let alone intelligent life. I think Earth meets a crazy specific set of criteria that is going to be astronomically rare.
