Cross-site tracking can have multiple purposes.
First, it can make your online experience effortless and overall better. Let’s take social media widgets again: if you run into an article you like, you just need to click the widget to share it.
Trackers can also gather details about your online activity to show you things like personalized ads. This type of cross site tracking isn’t inherently bad, but it needs regulating.
That’s where data privacy laws, such as the GDPR, go on stage.