It is definitely part of it. Only the top physicists are considered for the position.
I bet you that most people couldn’t tell you what Einstein did to win the Nobel Prize or how relativity works. Einstein is still one of the greatest physicsts of the past 113 years (have to add the 13 to cover the the year 1905).
If you ask physicists why Hawking is famous they will be able to tell you. This is why I say that Hawking was famous among physicists.