I think a good deal of the emphasis on Annette is because unlike Maria and Richter, she's being seen as a major character in the story, so I can understand some emphasis on someone who, besides her name, is a completely original character. I don't mind the backstory and the mysticism behind her powers being an episode. The issue is they only had 8 episodes, and the first half is just building the cast. I think we can all agree this show is trying to do a lot with a small amount of time.
By trying to have five main protagonists of importance (Richter, Maria, Tera, Annette, and Edouard) and eight episodes, it's going to flow poorly. Add Orlox, Emmanuel, and Erzebeth and you can see this is just stacked with characters in a runtime that can't cover it. This is a show that clearly needed twelve episodes. Not even the main antagonist has been covered well by explaining her power and motivations. I feel this is similar to season 3 of the previous show, but that had the reverse problem: nothing of note happens until the final few episodes because it's a filler season trying to explain and build up Carmilla and Isaac who are not the main protagonists. Nothing of note can actually happen until the final few episodes here because they have to explain who everybody is. The coolest moments were when Juste and Alucard appeared, and those were straight to the point. I already know for sure they didn't have time to build Juste up because there's just no time to fill it in, which is why they're already talking about more of him being in season 2.
You could tell they were pressed for time when so many episodes had characters meeting up with an amazing coincidence. Annette trailing Drolta and she just happens to find her vampire slave owner in the same random ass graveyard? It comes off as Saturday morning cartoon conflict resolution.