I love what you have written here! I grew up in the 90s and got a little bit of a tale end of the zine culture but really experienced it around 2010 when, in my little town there was a zine library. It was and is very much as you say "a reclamation of individual expression after too many decades of publishing homogenization". That is a great way to put it!!
It seems important to reclaim the individual expression when now it feels that there is a force in the world attempting to homogenize our thoughts. I don't want to live in a world where everyone is in lock-step and I hope that freedom of expression flourishes, even if the root is rebellion.
Interesting what you say about AI has democratized art. I am not so sure I agree, or at least, I don't see it that way. I have always felt that art is inherently democratic. One can make art with pencil and paper, or a sculpture with clay found in a mountainside. But, I do agree in that the common-ness of cellphones and the digital tools they provide gives people from all walks of life the ability to be content creators and send their words and work out into the world much more than in the analog world.
I hope you get back into scrapbooking and making such trades. I hope scrapbooking makes a comeback! That is something I miss from the 90s and early 2000s, scrapbooking parties were definitely a big part of my childhood.