UPDATE: Note: This was my first post on this forum and I apparently accidentally published it before finishing writing it, so a few people read it and commented before I got to ask my questions.
Also, my title is inaccurate. Such EA organizations already exist (among them, GiveWell itself, Charity Science, and Giving What You Can).
However, I would still like to emphasize my belief that the EA movement doesn't emphasize enough the value of donating to such "meta-EA charities" rather than donating to the most effective non-meta charities directly.
Most charity fundraisers cause harm because (1) they don't actually increase the total amount of money donated to charity, but rather just shift money from one charity to another and (2) most charities are less effective than the average charity.
However, fundraisers for the most effective charities do a lot of good because they redirect money from less effective charities to charities that have much greater impacts.
In response to the question, "What are you trying to accomplish?" GiveWell says it aims "to direct as much funding as possible of this large pool [of donations given by individual donors] to the best giving opportunities we can find."
But I don't think this is true. GiveWell's function appears to be identifying the best giving opportunities, not doing fundraising for them.
Which organizations are focused on doing fundraising for the most effective charities? Do they exist?
If so, why haven't I heard of them? (UPDATE: I had heard of the three mentioned in the comments.) Why weren't they mentioned in William MacAskill's new book Doing Good Better?
And why haven't any of them made the list of GiveWell's top charities?
It seems to me that it would be significantly better to donate to a fundraising organization that redirects funds to GiveWell's top charities than it would be to donate to GiveWell's top charities directly.
You'd have to take into account what would happen otherwise to be sure, but my initial impression is that this is true.
If I'm wrong about this, I'd very much like to know why.