> This makes intuitive sense too — an early Great Filter simply has to stop life from occurring,
I'm not so sure why this supposed to make intuitive sense. Life is a gradient, so any metabolic process that happens on a energy gradient can be considered 'alife'. I really don't see how an early Great Filter would work - are you going to stop energy gradients from happening? I've read -- will try to dig up the source -- that -- at least simple life -- is pretty much a given since -- even though it creates pockets of lower entropy -- allows for the most paths to thermodynamic equilibrium.
In my opinion a late filter makes more sense. That is; any species that evolves in the confinements of competition for resources and natural selection is -- due to the requirements that competition for resources creates -- necessarily unable to properly transition to a steady-state mode with no competition for resources and no (or limited) natural selection.
The reason for that is that the transition phase from competition for resources to the steady-state phase is simply too short. I'm convinced that this is what we are currently seeing with Humanity on a global scale; even though there's no need for competition for resources, we're still biologically and socially 'programmed' to compete with each other for resources, mates and habitats.
(Biologically, all humans are more closely related to each other than -- for example -- any two chimpanzee tribes. We are not very diverse, genetically.)
That inability to quickly change a species 'modus operandi' to a steady-state model together with the immense power multiplication of technology and cooperation that make it possible for civilization to literally dominate their ecosphere, I don't see how any species is ever going to survive that threshold.
The result of that inability to switch to a steady-state model and the powers achieved - tools and cooperation are the ultimate exploits! -- is simply extinction by habitat destruction.
I think that the current observations quite neatly match this.