From our 1 datapoint set I’m leaning towards the “earth is an aberration” theory. This was a dinosaur planet. There was a reset some time ago that cleared the path for mammals. It’s unlikely that this timing is common.

It was recently proposed the hypothesis we suceeded at developing intelligence while dinosaurs failed because humans evolved under the lowest levels of atmospheric CO2 in the entire history of Earth, allowing brain upscaling, at least until we botched it in the last 2 centuries. See https://www.qeios.com/read/IKNUZU