It's one of those series that you look back on and think: that didn't really go anywhere, now did it?
It's an okay concept but I guess the problem is that they kept fucking around with the status quo too much and Jackie was a bit too overpowered unless the story required him to not be. They never really managed to come up with a steady long term status quo with a working rogues gallery to fight beyond the Angelus and, iirc, the stories tended to revolve too much on people trying to steal the Darkness.
The book never really had Marz' Witchblade type strong creator oriented run to make the book legitimate beyond its meager T&A tease with action origins. The only time the book was somewhat getting to that territory was after Artifacts rebooted the entire universe and Jackie had his dream life but it was corrupted from within. That had plenty of potential that never really matured in a satisfactory manner due to how rushed it was. I can't help but to think the book would work better if Jackie was more of a guest star in it rather than the protagonist. Go for the post-weird bum superhero Spawn era angle that wss building up to Spawn #100, where your title character is more of a mythical presence in the shadows, and the focus is largely on normal people stumbling into him. The Darkness as a book should be more about Jackie as a modern day boogieman and the supernatural fringes surrounding him rather than him specifically continuously fucking his own life with bad decisions.