I generally agree with parts of this.
For example, I think the writing, screenplay, cinematography etc in FATWS is "good" in the sense that it was cohesive and consistent. It's visually entertaining. The FATWS series story itself is not bad or poorly written. The actors themselves are certainly not bad. The production value is at the same level we've come to expect in the MCU.
It's the characters of the Falcon and the WS as a concept that fails the story. Unfortunately, superhero stories are inherently character-driven, and I think these particular characters conceptually let down the entire production.
The overall critical analysis of performance art/literature/etc is dependent on a large number of individual captions - things like story, dialogue, character development, actor performance, musical effect, cinematography, and on and on and on. Any one of these captions can be an individualized opportunity to demonstrate excellence, as you noted. But some captions are weighted more than others, and this is also genre dependent (writing is more important in some movies while special effects are more important in others). And if a highly-weighted caption fails to deliver, it can bring down the entire production, regardless of other individualized excellences.
Rather than sheet sundae as a metaphor, let's try an actual cake metaphor:
If I'm trying to bake a cake, and I have flour, eggs, sugar, frosting, and sprinkles, I have a pretty good cake. If I have flour, eggs, frosting, and sugar, but I'm missing sprinkles, I still probably have a respectable cake. But if I only have eggs, frosting, sugar, and sprinkles, I don't have a cake at all, because I'm missing a critical ingredient.
This is the problem with GoT Season 8 and it's the problem with FATWS. GoT was missing the critical element of cohesive writing. FATWS is missing compelling leading characters. No matter how high quality the other ingredients are, these two things aren't cake. They're just good ingredients in search of cake.
Thanks for coming to my TED Talk.