Intervention dominance arguments for consequentialists
There's a fair bit of resistance to long-term interventions from people focused on global poverty, but there are a few distinct things going on here. One is that there could be a disagreement on the use of discount rates for moral reasoning, a second is that the long-term interventions are much more strange.
No matter which is chosen, however, I think that the idea of "donate as much as you can per year to global health interventions" seems unlikely to be ideal upon clever thinking.
For the last few years, the cost-to-save-a-life estimates of GiveWell seem fairly steady. The S&P 500 has not been steady, it has gone up significantly.
Even if you committed to purely giving to global heath, you'd be better off if you generally delayed. It seems quite possible that if every life you would have saved in 2010, you could have saved 2 or more if you would have saved the money and spent it in 2020, with a decently typical investment strategy. (Arguably leverage could have made this much higher.) From what I understand, the one life saved in 2010 would likely not have resulted in one extra life equivalent saved in 2020; the returns per year was likely less than that of the stock market.
One could of course say something like, "My discount rate is over 3-5% per year, so that outweighs this benefit". But if that were true it seems likely that the opposite strategy could have worked. One could have borrowed a lot of money in 2010, donated it, and then spent the next 10 years paying that back.
Thus, it seems conveniently optimal if one's enlightened preferences would suggest not either investing for long periods or borrowing.
One obvious counter to immediate donations would be to suggest that the EA community financially invests money, perhaps with leverage.
While it is difficult to tell if other interventions may be better, it can be simpler to ask if they are dominant; in this case, that means that they predictably increase EA-controlled assets at a rate higher than financial investments would.
A good metaphor could be to consider the finances of cities. Hypothetically, cities could invest much of their earnings near-indefinitely or at least for very long periods, but in practice, this typically isn't key to their strategies. Often they can do quite well by investing in themselves. For instance, core infrastructure can be expensive but predictably lead to significant city revenue growth. Often these strategies area so effective that they issue bonds in order to pay more for this kind of work.
In our case, there could be interventions that are obviously dominant to financial investment in a similar way. An obvious one would be education; if it were clear that giving or lending someone money would lead to predictable donations, that could be a dominant strategy to more generic investment strategies. Many other kinds of community growth or value promotion could also fit into this kind of analysis. Related, if there were enough of these strategies available, it could make sense for loans to be made in order to pursue them further.
What about a non-EA growth opportunity? Say, "vastly improving scientific progress in one specific area." This could be dominant (to investment, for EA purposes) if it would predictably help EA purposes by more than the investment returns. This could be possible. For instance, perhaps a $10mil donation to life extension research could predictably increase $100mil of EA donations by 1% per year, starting in a few years.
One trick with these strategies is that many would fall into the bucket of "things a generic wealthy group could do to increase their wealth"; which is mediocre because we should expect that type of things to be well-funded already. We may also want interventions that differentially change wealth amounts.
Kind of sadly, this seems to suggest that some resulting interventions may not be "positive sum" to all relevant stakeholders. Many of the "positive sum in respect to other powerful interest" interventions may be funded, so the remaining ones could be relatively neutral or zero-sum for other groups.
 I'm just using life extension because the argument would be simple, not because I believe it could hold. I think it would be quite tricky to find great options here, as is evidenced by the fact that other very rich or powerful actors would have similar motivations.