If this situation persists, we would be left without an important pollinator of plants. Without them, we would not have fruits. Without fruits, we would not have seeds. Most people don't grasp the seriousness and severity of the situation and impact of it, and I don't think they ever would.
That is how I think the world would slowly come to an end, because humans are too selfish and pre-occupied with their own desires and ambitious dreams to care about the environment and its plant and animal inhabitants. Maybe I am just a pessimist where the future of the environment and world is concerned. I hope this day would not happen in my lifetime because I don't want to be around when armageddon happens.