Suppose you have several different, similarly good plans to build a nuke. (Sure, not an EA goal, but it makes the rest of the analogy work) You have a single critical mass of uranium. Trying to split it between both projects would guarantee that neither succeed. Neither one would have the critical mass. Switching is costly. Sometimes, gains aren’t sublinear. If you need a minimum scale to get stuff done, and are faced with 2 equally good projects and only resources for 1. Sometimes the best solution is to pick one project, put all your resources on that, and stick with it (unless it goes really seriously wrong.)
Suppose you have several different, similarly good plans to build a nuke. (Sure, not an EA goal, but it makes the rest of the analogy work) You have a single critical mass of uranium. Trying to split it between both projects would guarantee that neither succeed. Neither one would have the critical mass. Switching is costly. Sometimes, gains aren’t sublinear. If you need a minimum scale to get stuff done, and are faced with 2 equally good projects and only resources for 1. Sometimes the best solution is to pick one project, put all your resources on that, and stick with it (unless it goes really seriously wrong.)