Even if people pick interventions at random, the more people who enter a cause, the more the best interventions will get taken (by chance), so you still get diminishing returns even if people aren’t strategically selecting.
To clarify, this only applies if everyone else is picking interventions at random, but you’re still managing to pick the best remaining one (or at least better than chance).
It also seems to me like it applies across causes as well as within causes.
Even if people pick interventions at random, the more people who enter a cause, the more the best interventions will get taken (by chance), so you still get diminishing returns even if people aren’t strategically selecting.
To clarify, this only applies if everyone else is picking interventions at random, but you’re still managing to pick the best remaining one (or at least better than chance).
It also seems to me like it applies across causes as well as within causes.