This is the form for ESTA, the travel authorization one must obtain if entering the US under the visa waiver program by air or sea. On the visa application forms, the social media questions are not optional, though still limited to a particular list of social media sites. The visa form is used people from countries who are not in the visa waiver program as well as who are not entering under the VWP (for example workers, students, journalists, tourists/business travelers staying longer than 90 days, and immigrants).

Not sure under which rock you were hiding all this time, so here you are:

https://www.bbc.co.uk/news/technology-48118558

https://eu.usatoday.com/story/tech/2019/05/01/u-s-customs-ca...

https://www.zdnet.com/article/warrantless-phone-laptop-searc...

Please edit personal swipes out of your comments here.

https://news.ycombinator.com/newsguidelines.html

I was referring to "give away a list of all their social media accounts and all their email accounts", not "If you ... you must now share that information". Your references make no mention of the former.