(Disclaimer: as I said, I don't work at Bing anymore. Things may have changed in the intervening period and I could be mistaken or plain wrong about things)

Obviously ranking search results is immensely complicated with lots of accumulated insider wisdom, but the short answer is that "static" page features (PageRank, how well the query matches text on the page, etc.) are good for pruning down zillions of pages to generate a candidate list of 10 or so results to show the user, but not great at ordering those results, and serving the results in the best order is really important for user satisfaction. For generating the final top-10 ordering, "dynamic" features like how many people clicked that link, how long did they spend on the page, etc. are the most useful.

Regarding what is tracked, obviously Bing can only track what you're doing on Bing itself, so clicks on blue links and backs are tracked, but they can't see what you do on the destination page. This data is used to train models/NNs/etc. but the raw click data isn't kept for very long: it's too large and it has to be removed for GDPR compliance.

> For generating the final top-10 ordering, "dynamic" features like how many people clicked that link, how long did they spend on the page, etc. are the most useful.

Do Google do this as well?

I've never worked there and can't say for sure, but I have to assume that the broad strokes of their search engine are the same as Bing's. Bear in mind my response above was a very very high-level description of a really complex system with tens of thousands of person-years of accumulated knowledge and experience inside it.