But for the MC, it goes Maomao>Frieren
Even if you remove Frieren as the mc, I feel like you could still have certain other characters running the series such as Himmel.
But for The Apothecary Diaries, Maomao kind of carries the series, remove her and I don't think any other characters probably not even Jinshi would be able to carry the series.
Well, I'll agree that Maomao carries the show for the most part, but I don't agree that if you remove Maomao that it would be a boring series.
To elaborate a little bit on that, the stage which Maomao's story plays in has many other angles that are less explored in the series but that still carries a lot of potential for interesting storylines and plotlines.
In other words, we are following the story from mainly Maomao's perspective, hence she is the star of the show, but you have many other players, like you said Jinshi for example, who would be just as interesting to follow - if they were given the spotlight.
As for why I think that is because the setting of being in the Royal Palace where Political Intrigue, Schemes and plotting is looming over the entire palace at any given time - where any character of some relevance would be interesting to follow for that reason alone.
Maomao works because she finds a great balance with Intellect/ Knowledge & Humor/Charm, and also her position in the palace where she is in close proximity to the majority of the most important characters and their struggles.
Also you could even take a completely different route and focus on the pleasure district, there's without a shred of doubt an arena where a lot of intrigue and intel finds its way
TL;DR
The show can defo work without Maomao, but there are so many angles that could be explored from many characters in the story that it would stand on its own legs.