We should be about enlarging rather than reducing. We should be multiplying the names for things, not boiling them down to one. We need a Doctor-Who-Object-Oriented Ontology (DWOOO).
I think there can be reduction but not to an absolute bottom nor a final resting place. I can understand that some want to work with objects, some with events, some with relations, and some with substances. And I can respect the turn away from the priority of epistemology that Graham Harman and others advocate.
But things are bigger on the inside then they are on the out. They are much bigger. This is what the Doctor says of the TARDIS but I think it is about all things. To put this in the terms of Thomas Aquinas' theology of the creature, creation is the depth of mystery. I can take issue with lots things in Thomas' theology and philosophy but this is the most important that I've found. If what a thing is is its relation to God, that is, its essence and existence alike (in Thomas' terms), then there is a kind of mystery appropriate to creatures. Things may appear one way but there is a depth to them, an abyss that opens once one contemplates the most common chickadee and the most sublime natural scene.
No one can say what a thing is for sure -- not because what they are is simply too small to view (Locke) or because of a difficulty with our mental or sensory equipment -- but because we are dealing with a mystery that always remains in all things. Is God an event, a person, a being, a constellation of relations, a being-beyond-being? The reductionist wants one of these, perhaps two. God is that which makes things the mystery that they are.
The only way to get at things, though in this mystery, is not the positive depth that they disclose but the moment of injury. We can't think that our efforts to reduce and squelch the mystery of things are so easily overcome. Rather, it is the cross, the theologia crucis that opens up the way to disclose the truth of things. When we try to get at things to name them one thing, to siphon off their mystery and freedom, that moment, that pain, is the pain of the cross and so the point at which we might discover the depth of all things.
You might say that this is all a new form of an old theology. You'd be right. It's the real name of that ancient writer hidden behind a psuedo-nym: Dionysius the Areopagite. And one more Doctor, whose theology is usually taken to be the opposite of that so-called Dionysius: Martin Luther.