(feels quite fucky to type the following without coming across as a naysayer; not quite the intended meaning, but.. I guess you'll see)

it'd probably be cool if this could exist, but also there's a couple of extremely hard problems in going for it, along with a couple of (to my current knowledge) entirely unsolved ones

one of the presently-unsolved things I know of is that we don't yet have anything like scalable performant homomorphic encryption so there's no way to do fully-private query operations on a dataset, which thus gives way to the operator snooping space combined with user privacy angles. there are some technical solutions to some aspects of this, and a number of social things that would apply too

might be interesting either way

definitely a hell of a big project.