Curate, connect, and discover
"I didn't comment on a fic I liked because I don't think the author would care or remember my comment anyway". fanfic writer here, I still remember comments I got on my fics from seven years ago. I still think about them and they still make me smile. your kind comments are what motivates us and what helps us keep writing.
I personally know writers who take screenshot and print out comments they got from their readers.
TL;DR comments matter to us writers more than you think. if you like a fanfic, never be shy to let the author know ♡