Peer review has been a thing since, albeit in a much less rigorous way, at least the XVII century. The so-called 'republic of letters' was a world (europe) wide society of philosophers, mathematicians, and early experimenters sharing results and data in writing. Mathematicians have been publishing proofs and challenging each other in Europe since at least the Italian Risorgimento...
Does the fact that it’s old mean it’s part of the scientific method?
That fact that it's part of the scientific method makes it part of the scientific method. I was addressing the "is it recent" bit.