Also, in the sorts of campaign I play, there is no "larger story". The PCs are the main characters of the story.
At the moment. Two years and twelve adventures down the road the party lineup might have ship-of-Theseus-ed its way into a complete turnover, and at that point those are the main characters in what is
still the same (emergent) s
tory!
If they were all to die, it'd be a different campaign entirely. I suspect this is another major difference between us.
Characters A,B,C,D and E start the campaign.
During adventure 1, A dies and B gets captured, replaced by F and G.
Adventure 2 starts with C,D,E,F,G. E dies, B gets rescued, H replaces E.
Adventure 3 starts with B,C,D,F,G,H. C dies; player turnover sees F retire and I join.
Adventure 4 starts with B,D,G,H,I. G dies, replaced by J. H and I split off to form their own party, replaced by K and L here.
Adventure 5 starts with B,D,J,K,L. D and J die, replaced by M and N.
Adventure 6 starts with B,K,L,M,N. B dies, replaced by H and I, who return.
And so, adventure 7 starts with H,I,K,L,M,N. At this point the whole lineup has turned over at least once, and in some cases twice; yet there's
no question that it's still the same story and still the same campaign.
And in case you think the above is a ridiculous example just to prove a point, I'll lob this in: I've DMed parties that had more turnover than this
within a single adventure.