Still trying to get my bearings in Powers's The Overstory

I really need to spend more time w/ Richard Powers's The Overstory (2018), as I'm now about +15% into the novel - but it's  +500-page novel! - and I'm not sure what it's about, and not sure whether it's worth that big an investment in time. So far, the novel consists of several short (10 pp or so) sections, each about a family that for one reason or another plants a tree or stand of trees to you might say accompany them on life's journey, sometimes over the course of several generations. Of the 5 (I think) I've read so far, the first 4 families (and their trees) end in tragedy (e.g., a stand of elms succumbs after several generations to dutch-elm disease, as the families is largely eradicated through a CO asphyxiation; another section ends in suicide, another focuses on the violence of a father, particularly toward his eccentric, possibly "on the spectrum," son). I'd feel more engaged and propelled to read on if these segments were more nuanced and vital, but each reads like a summary of a life, a sketch or outline for a novel, without the emotional richness of a short story. Yet I know that Powers has his sites set on something higher, perhaps something like the relationships between humans and nature, perhaps later sections to be told from the POV of the trees, with their multi-generation life spans? I do know that another 450 pp of stories/sections/segments in the same vein will be tedious going. Powers is among our most thoughtful and original novelists; I haven't read a lot of his works, but what I have read shows a writer with a wide range of knowledge (and a facility for research) whose books (about AI, for ex.) don't fit in well with any school or camp or style. I've also read that he composes by dictation into a voice-recognition device, which seems to me amazing (Stendahl and, I think, Dostoyevsky did the same in a 19th-century version, which partially explains the headlong rush of their plots - we don't see the quite same thing with Powers, although it may explain the abundance of plot lines and characters, none, so far, developed w/ much nuance). Further thoughts to are to come.