Yes but if one has many of these disabled or logged out (the social media-type pages in particular) I imagine they couldn't get much for the sake of heuristics

Yes but if one has many of these disabled or logged out (the social media-type pages in particular) I imagine they couldn't get much for the sake of heuristics data collection anyhow,or if say you log in from a device where none of these accounts are also opened. I can't imagine Facebook openly letting a third party banking site or app scrape up its precious specific user data without first paying for it in "anonymized" form, ditto for Google, so how might that work if the bank was attempting that?