I suspect it has something to do with the multi-seasonal format that Netflix tends to push. If you make something with that expectation from the start, it's imperative to make viewers want more so that your show will be renewed--by NOT providing closure in the last episode, by NOT tying various loose ends.
And even if screenwriters do have a clear idea of what kind of story they want to tell, there's always the risk of the show being less interesting in its next seasons, since the screenwriters have poured most of their good ideas into season 1 to capture viewers in the first place--making the story repetitive or stretched thin rather than more complex (and more captivating).
As a sort of aside, you know how "classic" Kdramas with, say, 16 episodes tend to falter in its last third? It's basically a similar problem with the multi-seasonal Netflix Kdramas, I think, but this faltering of narrative, so speak, becomes more obvious because you see it play out longer, not just in the last 4 episodes of a drama, but in the whole season 2 or 3 of your favorite shows, after you patiently waited for six months (if you're lucky) or three years. The disappointment becomes greater because you've invested so much good will for them (that waiting period is no joke).
Never watched What Happened in Bali, but I did start watching Kdramas in 2003/4 so it's been a while.