Facebook and Google have an incentive to track their users because they sell targeted advertising.
Even without ads they would have a very strong reason for tracking: trying to make the product better. Things you do when using Facebook are all fed into a model trying to predict what you like to interact with, so they can prioritize among the enormous number of things they could be showing you.
Even without ads they would have a very strong reason for tracking: trying to make the product better. Things you do when using Facebook are all fed into a model trying to predict what you like to interact with, so they can prioritize among the enormous number of things they could be showing you.