Every client I have averages ~30 third-party scripts but discussions about reducing them with stakeholders end in “What if we load them all async?” This is a good rebuttal because there are right and wrong ways to load third-party scripts, but there is still a cost, a cost that’s passed on to the user. And that’s what I want to investigate.
Yes, performance is a major concern. But it's not just the loading time and final weight of those scripts, there are all sorts of concerns. Dave lists privacy, render blocking, fighting for CPU time, fighting for network connection threads, data and battery costs, and more.
Check out Paolo Mioni's investigation of a single script and the nefarious things it can do.