You can find that information in review papers. Once information has solidified enough one of the main researchers will write an account of the current state of the field.
I'm really grateful that those review papers are being made, but they're not a very accessible source for non-experts. How do I find them? How do I know if a given review paper is exhaustive or not? If it's still relevant or has been superseded by another one? What I'm suggesting is to generalize the work being done to create review papers into a resource that is easy to find, authoritative and continuously updated.