Nowadays there is Aurora Droid that solves the curation question: Aurora Droid supports F-Droid-like repos, you can have multiple selected, and they may includ

Nowadays there is Aurora Droid that solves the curation question: Aurora Droid supports F-Droid-like repos, you can have multiple selected, and they may include proprietary applications. All usual issues with Android's security getting in the way still applies though. Overall Aurora Droid is still miles away from a "proper" store, because there is no payment, there is no user feedback (so apps are still ordered by last updated or name...), and I don't think the author plans on adding such features (Because it also requires backend work). That's still a nice update to F-Droid original app.