Is There a Difference in Timelines?

It seems like there's this much difference in opinion about when things are going to happen. So I never understood people who said never. That just requires some magical ingredient, which is not part of physical matter and hardware. But anything else is actually not that different. If someone says five years, someone says 20, 25 years, does it make any difference whatsoever? It's within our lifetime. We still need to do something about it.