Well, there's one setting and a lot of the story happened in the past, so, yes, it's true that you don't see all the elements play out (except for the denouement).
But the play lets you get to know the (surviving) characters and relationships, plus the important family element, and from that I think the richness of the story can be appreciated. I see that as a wonderful talent of the playwright.
My response was the opposite of yours - I think of it as an epic family story, enriched by the specific political situation of what happened before and the results of all of that. I was completely immersed in their situation by sharing this limited kitchen time as many characters came and went.
There are different ways to tell a story and this isn't a way that you, and others, don't respond positively to. While others do. So, what you're missing is a method of storytelling that works for you (and it's an expensive way of finding that out, though the same sentiments have been expressed here, amid the praise, since the production started).
I've definitely felt left out of the fun/enjoyment for plays and musicals - that's art.