Data maybe the new oil, which I don't agree with, but it looked about like this https://en.wikipedia.org/wiki/Petroleum_industry_in_Ohio#/me...

You can call data the new oil when someone invades a country to secure a data center.

I don't think anything fell out of favor and things are a long way from data being, "your data only" although you have been given some rights in that regard.

Nothing happened to it. Big data always represented pushing the boundaries of what could be done when dealing with large amounts of data. After a while the technology matured to the point where working with large datasets just became something you did. There was a lot of hype to it and many organizations unnecessarily went along for the ride. It's also a balance betwee current technology and economics of compute, storage, networking, etc. As the balance changes what and how you do things also changes.