So for the kinda replayability I want (where almost the entire storyline is different between playthrough A vs playthrough B... and I mean that extending to the problems you deal with and the enemy you face... almost entire plot line changed out) would require probably a short play-through on each run.
Like assume a 20-30 hour run for one play through rather than 60-100 hours that a lot of CRPGs get to. But have enough plot modules that you could have 100-200 hours worth of story or so and have DLC be further plot lines that can develop or side-quest models and such. Wildermyth is sort of good for this, actually because of all the random story events that you can run across. Though I'd prefer a more choice driven story than an RNG one.
I'm not going to dive right back into Bloodlines immediately after finishing it once because it's really just going to be the same story completely over again.
Replaying 60-100 hours of story that's not going to change too much isn't appealing. I may let it set a while and come back to it some other time when I feel like returning to an old story.
"Oh, I can do Baldur's Gate 3 with different party members"...isn't really going to encourage me to replay it immediately. It's minimally replayable.