What is money really? Is it just people's attention? Isn't that what Facebook is capturing then selling off to advertisers? Isn't that what Bitcoin is doing as

What is money really? Is it just people's attention? Isn't that what Facebook is capturing then selling off to advertisers? Isn't that what Bitcoin is doing as well? Capturing people's attention as well as development resources (minds/energy) from some of the smartest people right now?