So unfortunately, buying their labor at cheap rates seems to be the best way to transfer wealth right now, at least a big scale [0].
[0] - On a smaller scale individuals can donate to charities like Against Malaria Foundation or GiveDirectly, which I highly recommend everyone does if they have excess wealth.
This is not the only option, and this defeatist attitude is dangerous. There are many charities operating in third-world countries that are incredibly efficient and are delivering real impact right now. Here’s a few: https://www.givewell.org/charities/top-charities
Now, obviously scaling it up will be difficult, but all these charities are currently cash constrained, so there’s still some room to grow, and after that point, I’m sure it’s not an intractable problem to figure out a working model.
The “corrupt government” excuse is common one to justify inaction, but given the existence of so many organizations doing good work, I don’t it’s applicable anymore.
It would make the ultra rich a tiny less richer, but hey you can't have that. There is wealth in this world so that every single kid on that planet can go to school instead of working at the factory, it's just insanely badly distributed.