Without a subject, there is no object, like there is no left without right.
The problem of all philosophies making the object independent of the subject, like OOO, is that the object (in general) depends on the subject. How can an object exist without a subject? The more the subject is excluded from the interaction, the more ideal and fleeting the object becomes.
Making the existence of objects completely independent of the subject implies a naive comprehension of the world. This is a case of philosophy based on fallacies (cf. Heidegger, Husserl and Hegel (dit 'dialectical absurdities' by mario Bunge)).
If all objects exist in an independent reality, don't accept they are what we human think of them, but go deep: what are objects? For example, is the tree the one existing, or is the leaf? Some would naively answer "the tree", and we can retort "isn't a tree part of a forest? So, is it the forest or the tree, the object?"
The object is always determined by the subject. If the subject vanishes, there is no object.
This is easy to demonstrate in multiple ways. For example, trying to determine where to find an object: what is the standard spatial frame of reference? The size of an atom? If so, all objects in the universe are not substances, but forces, and the only objects that exist are atoms.
Another example: what is the standard chronological frame of reference? The existence of an electron? If so, time would not exist (in addition, time is just human memory). So, do trees exist, view from an instant, or view from eternity? Hardly.
OOO overemphasizes objectivity, neglecting the complex relationships network between objects, and the inevitable interaction subject-object, which enables the existence of the object.