Earlier quoted context omitted.
That's certainly a logical opinion, and I agree that efficiency is key. However, I think it's also important to keep in mind the personal value of traveling on aid trips, which allow for an improved understanding of the need that lies. Perhaps this encourages potential donors to increase the frequency and quantity of their contributions.
I'd liken it to the classic criticism: "charities spend too much money on advertising!" But how do charities get donations without advertising? How do they let people know why they need the money and encourage them to donate? At some point, yes, a charity can spend too much of its donations on advertising, but advertising in general is a necessary evil. Same with this. The charities might take in less overall if they…
This isn't 100% useless, as it causes economic activity, but it's done under the lie that non-profits are de facto good things.
This is the challenging thing about charities. If I want to evaluate the person selling me socks or smart phones, I look at the good they offer and decide if it is worth $N. If it is, I make the trade. If not, I don't.
But with charities, you have to figure out "is the marginal change the charity will do with $5 worth me having five dollars less?" And that's incredibly hard to figure out. Even the charity itself, assuming it even wants to know, can have a hard time figuring out the net difference of five dollars.
Which is the whole point of effective altruism.