It’s true that a lot of data isn’t sold, but a large chunk of the figure you quote also seems to include business data — stuff that contains zero personal information but is still hugely valuable to companies and investors (look at how much this report costs, for example, or consider that a Bloomberg terminal costs around $25k/yr).
And remember, those investment buyers make up a big chunk of the consumer data market too and are only interested in aggregated insights to inform trading strategies. They don’t care about personal info or targeted ads.