It is typical of the hubris of us individual humans and our individual human societies to always imagine that we alone are big and mighty and wise and that all other beings are small, weak and foolish.
A further human hubris of ours is to imagine how better our imagined Utopia would be when all the other, lesser/weaker/smaller forms of life have been liquidated, if need be with with extreme prejudice.
But germicides won't ever remove all the germs anymore than insecticides will ever remove all insects or eugenicides will ever remove all the weak, frail and elderly.
The various forces of Nature combine to interact upon all beings in various ways depending on scale, because each individual scale works over a particular - limited - spatial and energy scale.
Reality , the Reality of matter and energy , is thus permanently stratified into different layers or scale levels.
From the point of view of possible lifeforms, that means a variety of scale-defined niches that are permanently ("eternally") available for the lifeform best sized to excel in them.
Translation : kill off all bacteria sized life and some new life the same size will emerge to fill in that hole of opportunity.
Humans are currently the "fittest" for our big niche but we are not "fit" for all niches, though we continue to delude ourselves into thinking so.
Niches change constantly at the margins so all successful lifeforms display a variety of members, some who appear to be weak and useless, but in fact this merely an evolutionary way to ensure enough variety in the lifeform's generic material to surmount unexpected changes in their chosen niche.
For example , people with a moderate form of the disease of sickle cell anemia survive some insect-vectored diseases better than supposedly healthier people, at least in the many large regions of the world where these insects and diseases are endemic.
The big and the small lifeforms may never grow to like each other or cooperate with each other, but they might as well resign themselves that the big and the small, like the rich and the poor, will always be with us.
Henry Dawson grew to understand the profoundness of the concept of "eternal commensality of the big and the small" in his studies of human-oral commensal strep bacteria interactions.
That is why he was so damn adamant that even winning WWII couldn't come at the cost of tromping all over the weak and the small....