What is the convincing evidence for the authoritativeness of the consensus of the eras after the Companions?

The proofs for the authoritative nature of scholarly consensus (ijma') do not differentiate between one era and another. The same proofs used to establish its authority during the era of the Companions also indicate its authority if it is formed after their era. Scholars have pointed out that the disagreement is not concerning the authoritative nature of ijma' after the era of the Companions, but rather concerning the possibility of its realization due to the vast expansion of the Islamic lands and the dispersal of scholars.