Good comment. The point is to experience the oneness - and there is a definite experience of that state. Without that basic experience, it is just ideas and words. After the experience, two things happen: firstly, we return to our standard duality with a new perspective; and we also have the opportunity to integrate that inner core with our daily life.
Think of it a base or root consciousness - I'm not a fan of quantum mechanical analogies, but here it comes! It is somewhat like the ground state, where apparently nothing exists yet is the source of existence.
Yes, we are all connected, but that does not mean one amorphous hive-mind blob of consciousness; it means we have the same ground state. hence, it may be possible, one day, that we may all agree on reality!