And... surprise! It's analytics, tracking, and advertisements!
What are you going to do as an engineer? Tell sales that expensive marketing solution they bought isn't going onto the site because it loads too much JS?
And some times you have to let things fail and then explain why it di and then do it right
No JS, no tracking, no nonsense. 100% content.
BTW I do this for a living for some big brands just dropped FCP from 2.6 to 2.4 and CLS .478 to 0.385 with some tweaks to the preload.