Just look at Supergirl and Green Arrow. Their shows might be successful, but their comic books are not great sellers. With those two having already problems, the more obscure characters don't have much of a chance.
Another problem is that many of these characters are to different from their comic book counter parts, or just don't really fit because the setting in the comics is different.
Flash is in the comics a solo character, so you can't suddenly a ton of other characters in his book.
Green Arrow main love interest in the comics is Black Canary, so there is no need for Felicity.
Artemis is in the comics a completely different character, who is neither Asian nor related with Cheshire, and has noything to do with Green Arrow or Wally West. And is actually part of the JSA Franchise. And non of the realtions she has with other characters she has on the show really translate into the comics, since the Young Justice team from the doesn't exists and never existed in the comics.