Times are changing. DC left Diamond back in 2020 and went with the newly-created Lunar. Later on, Marvel went and signed with Penguin Random House to distribute their comics with Diamond only able to be a wholesaler. Then IDW did it with PRH too. Now, Dark Horse will have its comics and trade paperbacks exclusively sold via PRH starting in 2023, as was announced this morning. It is wild to think before the pandemic hit that Diamond was the sole distributor of single-issue comics and now we've got DC exclusive with Lunar (and smaller publishers with Lunar and Diamond) and Dark Horse joining Marvel and IDW with PRH.
Wildly enough, when Dark Horse switches to PRH in June of 2023 that will make Penguin Random House the biggest distributor of comics in the Direct Market. Diamond will still have a hefty presence in comic and hobby shops thanks to its sales of toys, collectibles, trading card games, and the like, but their monopoly over the comic industry they held so long fell from power shockingly fast. The distribution wars are back with a vengeance--I guess the 90s really are in style again.