There is never any consensus on anything. Yow couldn't get all people to agree that Nutella is best eaten without bread with just a spoon and we all know it is!
However, I am positive Fed would be clearly on top of the Goat debate if you asked the public, I am very confident he'd be on top if you asked say the first 1000 ranked players on ATP, and I am quite sure most historians would or will place him top.
No consensus, I completely agree, but a clear majority extremely likely. And if that is good enough to pick parliaments and presidents, well...