What Role Did Life Play in Preserving Life on Our World?

With venus, no planet wide magneto sphere, a horribly thick atosphere of carbon dioxide and sulphuric acid. On mars, low mass, dead interior, not a thick enough atmosphere, couldn't hold on to its atmosphere. And then with earth, we've got a large moon, keeping a stable but also probably no giant impact that rolled us over on our side, since the moon,. Right? We have this constant mixing going on from the tidal forces, where we see the ocean tides. This creates a small amount of heating. All of this comes together to put us in a situation where our planet is still mushy on the inside and driving a nice, healthy magnetic field