> But that's not how granting agencies work; they give out one or two year awards, with the understanding that those who are successful will apply for more funding later.
I've worked for a funding agency. It's tough to give out five year grants with no deliverables other than "be a genius". When you are funding basic research you have to be prepared for the idea that lots will fail, and many people will decide to leave. How do you know who is a genius when they are finishing their PhD? Everyone finishing a PhD at Oxford/MIT/Stanford/etc has a very impressive resume and the reality is you can't fund them all.
Two year grants seems a reasonable compromise here.