streetgeek,
I don’t think people can and do control everything, or ever will. But that doesn’t mean that they shouldn’t try and control nature for the benefit of mankind. Furthermore, this doesn’t mean that Hashem isn’t ultimately in control.
Dealing with kochem v’otzem yadi is a nisayon that we are meant to deal with. There is no gezeira that I am aware of to the effect that we should not harness nature for a good purpose becuase it might lead to kochem v’otzem yadi.