I mean, there are basically two styles of storytelling for modern serialized genre shows:
- "Slice of the arc" shows, These typically do not have identifiable episodes. Instead, they string together a number of scenes from semi-independent POVs into what can be a random 45+ minutes of the seasonal arc. Occasionally some sort of theme can be seen in a particular episode - particularly near the climax of the story. Stranger Things is one of these sort of series. Game of Thrones, The Expanse, and Altered Carbon are other examples which I can think of off the top of my head.
- Semi-serialized are the other version. These shows do have a coherent seasonal arc, but each episode still can have its own individual focus. These shows tend to be somewhat tighter in terms of narrative, as multiple seemingly unconnected plotlines are hard to integrate into a coherent episode. The Magicians is an excellent example of this. Others include The Mandalorian and The Witcher (somewhat of a hybrid, as the Geralt portion of the plots was episodic, while the Citi/Yennifer portions were arc-based).
Discovery started out attempting to be a "slice of the arc" show in its first season. However, this was more or less abandoned by the second season for semi-serialization with the occasional 2-parter thrown in. You can see the difference because if you think back to Season 1 we had the "check in with the Klingon" moments, and anything similar has now been thrown out the window. We now see everything from the POV of Michael and the others on the Discovery crew.
One of the ways semi-serialization keeps people interested is the characters have identifiable arcs even if the the season-long plots are relatively thin. This is accumulative however, which is why I think Discovery is partially failing here. I mean, if you think back to the first season, the number of genuine character moments was so limited it could be counted on both hands (Stamets and Culber brushing teeth, Michael and Tilly talking about burritos, etc.). Given the characters have so little history which has been established yet on camera, there's just not that much yet to call back to. Add to that that the show seems vaguely embarrassed by a lot of its own past, and it's basically just continually re-forming itself each season, instead of building on what was established before.