But how will marketing determine the effectiveness of their efforts if I don't "just add a single line of code" for every social media company to our website? </sarcasm>
While at the same time telling you (in their documentation) that due to script blockers and gdpr they just estimate (using more fancy terms and talking about ML & AI) the Conversions they report (and use for optimization).
They basically tell you: Trust us - we estimate your success in the best of your interest. As if they were a neutral party in that equation.