We are capable of both conscious rebalancing and unconscious rebalancing. To stand on two feet requires constant rebalancing. In fighting, I always want to be doing at least these four things: targeting vulnerable areas, improving my position, compromising my opponent's structure, and unbalancing my opponent. Meanwhile, I want to keep my opponent rebalancing unconsciously.
Once someone is way off balance, airborne or headed towards the floor, they are probably going to notice. If you can sweep them off their feet before they realize what has happened, that would be ideal.
The margin of human balance is so small, any movement requires re-balancing. Any incoming or outgoing force requires rebalancing. Even a very light touch requires rebalancing.
I suppose we could define "rooting" as an attempt to used the other person's feet for stability, or the other person's force to try and keep ourselves in balance. That's not the way people normally think about it, but it is worth pondering.
Anyway, all I wanted to say in this post is that if I can unbalance my opponent without them realizing they are off balance, it gives me a big advantage. The reason this advantage is so rarely used is that it is hard to trust--there are no visual or tactile cues.