In https://oliof.blogspot.com/2018/07/how-to-grow-audience-as-referee-ineptly.html I described a bit how I am organizing my current campaign, and a recent discussion on tabletop.social led to some discussions about coherency, emergence of story and other aspects that people assume happens when you do not have the tightly knit group of regular players you "need" to build a "coherent story". That I am putting these into quote marks should give a hint of what I think about this today -- for me it's not necessary at all. What follows are some thoughts on why a game without a stable set of players still can be satisfying in terms of "creating a compelling a narrative" ...
To begin, it might be helpful to have a player perspective on my campaign, and JollyOrc was gracious enough to provide one on his blog. Thanks for that!
So, for an individual player, the game doesn't feel much different because whenever they're participating, it's as if they're there; and when they are skipping one or more sessions, nothing happens to their character. It's actually a safer way to deal with absent players in terms of guaranteeing player autonomy than having PCs with missing players tag-along but doing nothing or similar, where a TPK can lead to even weirder situations. Many funny comic strips have been done about "My PC did what?!" or "My PC did idly stand by while what happened?!" situations, and these simply never come up in the way my campaign is organized.
It also means players that cannot attend the campaign, either indefinitely or for a while, don't feel the need to so something that is super destructive to their character (and often, in extension, the group or campaign). After all, they might just be back some time and continue following their long-term goals (such as Wolfgang the Artificer who was after a suit of armor to cast Animate Armor and finally got one and got to be awesome with it.