Nobody is pretending fossil fuels are not producing value, if they did not nobody would bother using them in the first place. The argument is about the fact that they produce relatively short term value for the person using them, at the externalized expense of polluting the atmosphere and causing long-term environmental instability and destruction for every subsequent generation for the foreseeable future. Coastal regions (and whole islands like the Maldives) disapppearing under the ocean is immense and ongoing value loss for humanity. Ocean acidification destroying marine ecosystems is an immense and ongoing value loss for humanity. More frequent and more extreme hurricanes is an an immense and ongoing value loss for humanity. And on and on...
I think a lot of people actually dont realize the value it gives humanity. Lots of people think we would have been better of in an alternate universe where we never discovered oil & gas.
How is this short therm value for people using them? They are drivers of the most fundamental stuff in our day to day lives. Either enabling billions of people cheap efficient transport, efficient agriculture producing cheap food, cheap and efficient global shipping of goods, a great portable and ajustable source of electricity.
I think as of now its a question on how much you are willing to sacrifice human welfare over preserving current nature/environment. Extreme weather has largely been solved for humans, the trend is still less death and starvation caused by extreme weather, we are immensely adaptable and resilient.
Im not sure our current pace of reducing emissions is that horrible. There are reasons to why it takes time. I might be too optimistic, but I think we will largely solve human issues. Nature as you point out, im worried about, although I know less about. And its hard to quantify what the value is for us.