Ehh that’s dramatic. There are plenty of (not great tasting) fakes. We can easily synthesize caffeine, and alcohol can come from fermenting plenty of fruits and other things. There’s also teas of numerous varieties. So we’ll be just as caffeinated and drunk complaining about how bad the shitty fake Hershey’s chocolate tastes.

All that aside, there are a lot of crops which are essentially monocultures that are in danger from things like disease and climate change. Bananas, coffee, cacao, even oranges.