Why donate to this, paying 10% to Patreon and possibly an unknown percentage to cover The Creative Fund’s overhead (if not, how will the project sustain itself?) as opposed to giving directly to the projects that deserve it most?

A much more interesting model for me would be something like a “last 20%” backer. Let users vote on campaigns that have 20% and and only a few days to go, looking very likely to fail. Winners get funded by The Creative Fund (provided its within a certain max funding threshold).