Without the web of life which is biodiversity, we could not inhabit the earth. Our soils are kept healthy and productive by the microbes, insects, fungi and small burrowing animals which turn vegetable matter into a kind of compost, and turn it over to provide oxygen and nutrients.
Plants put life-giving oxygen into the atmosphere via photosynthesis.
Our water is filtered through catchments covered in natural vegetation. Our food comes from plants which have been developed from wild strains, and crops are protected by the birds and insects which live nearby. Organisms in our rivers and oceans clean up the pollution such as sewage which are allowed to be dumped into them. And then there are the medicines and drugs we use every day which are products extracted from living material. They rely on biodiversity.