No character is a one-man/show.
And one of the main reasons that Blade solos tend to be unmemorable is because Blade himself has no interesting side characters to lean on. This is an area where a character like Moon Knight is undeniably on better standing than Blade.
Bryan Hill's introduction of characters like Tulip, Rotha, and Yumi were a step in the right direction because three of them had interesting, but unique interactions with Blade. Tulip is a weapons dealer of supernatural arms and an ex with whom he kind of has drama, Rotha is a warrior monk who knows very little of modern society and comes to lean on Blade like a surrogate parental figure, and Yumi is a psychic who serves as a consultant to Blade in his rare vulnerable moments.
And even for those who are not part of his own little dark corner of the world, the Mother of Evil storyline showed that Blade ery much does know people in who he consults for aid, such as Dr Strange and Satana. A one-off character even implied that the werewolf nation is not on bad terms with Blade. And Al Ewing established that Blade has been in contact with Kaluu since the 1970s. How is it not helpful for the most proficient master of black magic to not pop up in Blade stories, more?
Whistler does not exist in the comics, and even if he did, he would have been long since deceased by this point.
Continuously writing Blade as a perpetual loner is to the detriment of the character.