Root is probably the only one who deserves to finish with an average of 50.
Even then, I have question marks on his ability to convert starts into match winning tons.
Seen him give it away plenty of times when set and not go in and punish teams like an ATG would.
Amla, KP, AB, Younis and Cook are all above them IMHO.
Root is very young.
The issue of not converting starts is blown out of proportion IMHO.
Root is a lot like AB (but has a better cricket brain and temperament), they both find cricket too easy.
Cricket is so easy for them, they won't often go on barren spells where they fail to score a fifty+ in 6-10 innings like some players in their stature. They'll score 50's even when out of form, or get starts 40's and 30's.
They'll score 50's-90's when everyone around them is falling like a deck of cards. That is how good they are.
Take Clarke for example, he had plenty of barren spells, and I remember a commentator quipping without even looking at stats: "Clarke is on 35 today. When he gets such starts he usually gets a 50 and invariably converts them into big hundreds" , and he did exactly that scored 150 in the Ashes IIRC (Manchester?). After plenty of scores in the single and double digits. I think that was his first 30+ score in 10 innings or so. (NB. not that Clarke is in the same bracket as these two)
Some players are like that and Clarke isn't the only one, but not Root and AB.
I do hope Root finds that ruthlessness that AB lacks. It's too late for AB, but Root has age on his side. And has shown he's a match winner, whereas AB has never won anything for his country.
In fact Root is ahead of AB (who is highly rated here on PP, perhaps they're confusing Tests and ODI's), that's how good he is already in his career. Carrying your team at such a young age is unbelievable (not too long ago Cook was struggling), while a senior is moaning about workload. But let's not derail nor deviate from the thread.
Root won the Ashes on his own on the batting front, everyone was batting around him. He was scoring at 70 runs per hundred balls when Australia were skittled for nothing. Did the same in Jo'burg, scored a ton at 70+, and SA got dismissed for 80 as a group. Unbelievable talent is Root, he is far and away the best bat alongside Amla.