If 4chan can find 100 like-minded people to search for HWNDU flag in a total wilderness, including volunteers to drive around and honk randomly, then HN can find 100 like-minded people to write a single email.
Also, isn't this how the contact-your-senator-about-this-horrible-bill campaigns work? And they seem to be fairly successful, at least in the "contact" part.
Nobody has time or inclination to be part of your personal army unless it's entertaining lol.
I think you grossly overestimate how long it takes to copy-paste an email, especially in the age of AI - as well as underestimate the entertainment value of making bureaucracy squirm. And if the FOIA request makes sense in the first place, I believe the inclination would be self-evident (exposing corruption, holding government employees accountable, undermining big corps' exclusive access to information, preserving local history, etc.)