Re the third ‘mistake’, there is a long history of thinking that carrying capacity is a decent proxy for long term population. Is it a good proxy? Probably not in many situations. Is it better than extrapolating out the current growth dynamics for millions of years? Probably. My guess is that it is a simple defensible rough model here. And by laying out separate estimates for different scales being reached, there is also a pretty good sensitivity analysis. I think you are right that this could be improved by adding cases of permanent population collapse to the sensitivity analysis. But it won’t change the EV much. So again, I wonder if a superior critique would be: these estimates are more or less correct in EV terms, but we should be suspicious of EV.
Re the third ‘mistake’, there is a long history of thinking that carrying capacity is a decent proxy for long term population. Is it a good proxy? Probably not in many situations. Is it better than extrapolating out the current growth dynamics for millions of years? Probably. My guess is that it is a simple defensible rough model here. And by laying out separate estimates for different scales being reached, there is also a pretty good sensitivity analysis. I think you are right that this could be improved by adding cases of permanent population collapse to the sensitivity analysis. But it won’t change the EV much. So again, I wonder if a superior critique would be: these estimates are more or less correct in EV terms, but we should be suspicious of EV.