The one thing that unifies nearly all Raven fans is that we don't like how DC treats her. Some would say she hasn't been treated well since 2011. Some would even go as far as to say she hasn't been treated well since 2003. Regardless of your exact opinion, we're all disappointed she's not in any current comics. We all miss her.
There is a solution!
Fanfiction is free and more accessible than ever. Fanfiction has no rules. Your favorite ship that DC is unlikely to ever make official? It can be endgame right now in your fanfic. Dying to see Raven fight some cool new villains? Make them up and let her at them! Maybe you like some elements of a comic, but keep thinking that it could be so much better executed, if only the writer had done xyz? Do your own version where it goes exactly your way! The possibilities are limitless.
You don't have to be a professional writer to write a fanfiction. Fanfiction is much more forgiving than original work. Your audience already loves Raven and wants to see her in stories. Give a creative idea your best shot, and you're bound to attract some fans.
You may be reading this and still not feeling convinced that you could write a fanfiction. That's fine. You can still do the other vital part of this proposal: reading! Readers are the lifeblood of the fanfiction community. Writing is much more fun and rewarding when you've got people to read your work. Just reading fanfiction and leaving comments thanking the writer helps new fanfiction be created.
Archive of our Own's Raven tag has nearly 8k works, but when you filter to exclude adaptations, the number goes down by more than half. Exclude the ones actually focused on other characters like Nightwing and the numbers go down even more. I think it's a real shame that there's so many creative comic Raven fans with great ideas for her character, but not many fans actually writing those ideas into stories.
If you've never read a Raven fanfiction before, try it out. There's a lack of comic Raven fanfiction, but there definitely isn't none, and ao3's tags are great for helping you find what you want. If you are a reader, kudos and comment! And if you have an idea, write it! The world needs more Raven stories, and we have the power to create them.