> What kind of feedback can you get when the donation is not anonymous that you can't get otherwise? I really can't think of anything
I don't even know where to begin... This is like saying "what kind of feedback can you get when the products you buy are not anonymous." When I buy a phone or some set of products it's usually public in the sense that I go to forums to talk about it, or my friends see the products I use, etc etc and people see what I use and I get feedback of the "hey, there is this product that might do this thing you care about better"
Likewise, if what you care about is x and you just go and donate to some charity, nobody can tell you something of the form "hey, there is this charity that might do this thing you care about better"
Just like with products, de-anonymizing also increases trust when you see a positive review. Same goes with charities. It opens up a more worthwhile place where discussions can be held.
> yea, one can know if charity works without putting their name to it...
Totally true. Except you still run the risk of fooling yourself more if you keep it to yourself. I don't trust myself and prefer to defer to those who research charities for a living. I talk with these people a lot, tell them what my values are, and then get charity recommendations.
I suppose a counter-argument you might make is you can still engage with people anonymously and learn what you need. That I also totally agree with.
I think you and I might be using the word "anonymous" differently.
What I'm arguing against is a kind of charity that is anonymous where the person doing this charity is an island and doesn't talk to or engage with anyone or anything about it out of principle. I think a lot of people think this is a good principle to hold. I am completely opposed to it. Is there even one good reason to do charity in complete secrecy? Even if you prefer to be anonymous (which is completely understandable), it is still better to engage with people to learn why a charity is a "good buy."