Just can't agree with this line of thinking.This is because longevity itself is a criteria for 'greatness ' , i suppose . For instance i rate some one like Sachin sooo better when compared to Greg Chappel. Both averaged almost same in their career but Sachin maintained that in 329 inns where as Chappel did it in only 151 inns .Yes... Chappel deserves extra points in this one-one comparison because of him having played in a bit more tougher era for batting. But still to maintain the average in more than twice the number of inns is a huge gap in my esteem.Last 5 years of his career his wickets cast 54 runs each. And averaged 20 with the bat.
If he had retired before then he'd be in everyone's ATG sides
To put things in perspective Kohli was averaging almost 72 in NZL before his last series .But his average fell to a mere 36 by 1 series . What not he played only 4 inns in NZL last time. Imagine him having to play 6 -10 inns instead of this mere 4 in that sort of 'extreme pressure to maintain his own high standards'.....That is how tough it is to maintain high standards from time to time.So longevity is a huge factor which fans under estimate a lot when evaluating players