Scale is everything.
When we walk across a grassy field, we push the plants aside and brush away errant insects. Except for a few curious children, naturalists, and field biologists, that is the extent of our interaction with that ecosystem, unless we happen to see a deer, bird or other such vertebrate. We’re not required to engage with the moment to moment dramas of tiny invertebrates at our feet. We don’t keep a watchful eye out for marauding dragonflies ready to swoop down to attack as fiercely as any tiger. A sapling is, to us, not a tower so high that it is a region unto itself. All around us animals live and die, and we barely notice because they are so small, and we so large. Therefore, because it is no threat to us, we do not feel the need to exterminate the dragonfly in the same way we have done to the tiger.
This doesn’t make the dragonfly and its neighbors any less important on an immediate level. In fact, some of the smallest beings create the crucial foundations to all the ecosystems that we and other large beings rely on. The ocean would be empty without plankton; plants couldn’t grow without tiny fungal filaments at their roots. Even though most of these beings had lifespans that are only a few breaths of our own, without them we couldn’t be here. Still, for the most part we take them for granted.