One possibility is that there was not a strange hidden cause behind widespread stagnation. It’s just that funding slowed down, and so everything else slowed down with it. I’m not sure what the precise mechanism is, but this seems plausible.
FWIW, my sense is the opposite seems more likely: if growth in the number of EAs (and, particularly, EAs who founded organizations that seemed good) kept up, then funding would have matched the growth. Most orgs / funders that I’m familiar with are looking for more good ways to spend money (while not just embezzling it or w/e), rather than allocating limited funds among too many promising options.
[Related to other “would more growth be bad?” questions, one common way to ‘hack’ growth metrics is mergers and acquisitions. You could imagine the world where people went around to various other charities and groups, trying to get them to join the EA umbrella; the charts would look more ‘up and to the right’, but the underlying ‘innate’ variable might still be the primary factor in how many ‘real EAs’ there are.]
FWIW, my sense is the opposite seems more likely: if growth in the number of EAs (and, particularly, EAs who founded organizations that seemed good) kept up, then funding would have matched the growth. Most orgs / funders that I’m familiar with are looking for more good ways to spend money (while not just embezzling it or w/e), rather than allocating limited funds among too many promising options.
[Related to other “would more growth be bad?” questions, one common way to ‘hack’ growth metrics is mergers and acquisitions. You could imagine the world where people went around to various other charities and groups, trying to get them to join the EA umbrella; the charts would look more ‘up and to the right’, but the underlying ‘innate’ variable might still be the primary factor in how many ‘real EAs’ there are.]