One could also consider the general EA /β EA-adjacent sentiment over time as a cross-check on the risk of current groupthink. Of course, later EAs could be responding to better evidence not available to earlier EAs. But I would also consider the possibility of changes in other factors (like perceived status, available funding for EAs, perceived lack of novel opportunities in a mature cause area that has strong interventions with near-limitless room for more funding) playing a major role.
One could also consider the general EA /β EA-adjacent sentiment over time as a cross-check on the risk of current groupthink. Of course, later EAs could be responding to better evidence not available to earlier EAs. But I would also consider the possibility of changes in other factors (like perceived status, available funding for EAs, perceived lack of novel opportunities in a mature cause area that has strong interventions with near-limitless room for more funding) playing a major role.