What has happened? Well, people might not want to be confronted with it too much but we are in fact getting ever closer to a cataclysmic saturation point as far as the pollution of the world is concerned.
If you look at the world as a whole, it is a closed system. Which inherently means that there is a very clear limit on how much nourishment the world can provide and how much the world can be taxed in terms of garbage and so forth. We are literally getting quite close to hitting the cap on how much the world can handle.
Consider for example that the current extinction rate is 1000 the normal rate (throughout the history of the world, even outside of extinction level events, species go extinct at a certain rate, mankind has managed to increase that rate to 1000 the normal rate). Which still is nothing compared to an actual extinction level event (of which the world has seen like half a dozen over so over the course of the past 2500 million years or so) but still, it is alarming to say the least.
Bees, your example... are actually going extinct, slowly. This is not some conspiracy theory or anything, biologists all over the world have voiced concern over the state of bees for years now and in China there actually are efforts to replace the pollination of bees with manual labor. Not even joking. Now consider that very point of pollination. Bees (and other forms of life instrumental in pollination) are instrumental to the food chain. The food chain is built upon plant life. Without proper pollination, the food chain would collapse... hard.
And there are many other examples of this.
Is it hopeless? No, not at all. Life is incredibly resilient and, as I stated, the world has seen quite its fair share of E.L.E.'s over its history. It has always bounced back with a vengeance. So, we can still turn things around. But, until such a time as when we are in fact ready to do that in earnest, prepare to see things get worse before they start getting better.