TIL about the "The Boring Billion", a time period from 1.8 to 0.8 billion years ago characterized by more or less tectonic stability, climatic stasis, and stalled biological evolution.
Most things were using sulfur for photosynthesis and not CO2 and O2. Then tectonic events happened that caused O2 production to rise. Suddenly we had an oxidizing atmosphere that killed 80 percent of the diversity of life on earth while also changing the climate.
... that's what the great filter is about. The reason this is good news is that it suggests that the great filter was whatever leap happened after that billion year stagnation, and not, say, immediately ahead of us.