Training something like this costs millions. It’s not going to be useful to many people because of it’s size/the cost of doing anything with it.
I don’t think that giving alms justified the existence of feudal Lords. In the same way, I think the fact that nation states can’t keep up with the research expenditure of a few rich men (think space travel), shows us that we have a problem. That said, it does represent a fairly generous donation to science, start-ups, or whatever.
As far as I understand, you’d store eg tracking data in the POD. That would allow apps/services to give you better recommendations or personalized ads. The only party with any interest in writing to the POD is the end-user, but their interest is tiny. Better recommendations, so what? Advertisers prefer to keep their data private to have an edge over the competition.