The original sentence is fine  as it is written. It is difficult to improve upon originality.

   Keeping in mind that English is a very flexible language, all of the other sentenes  would also be sufficient.  However, the wording of the original  would probably be what I would write  to express the same idea.  Any sentence and idea can have many variations. I will show some.

Variation #1   "However, it is also true that  only those who  excel in  their profession

receive   huge salaries."

Variation #2   "Remember, it is  a  fact  that only those in the top ranks

of their profession obtain to the highest incomes."

Variation #3  "The  brute fact of the issue is that it is only those in the upper echelons

of celebrity status who obtain to the highest incomes."

Variation #4  "Insofar as any discussion of high income pertaining to celebrities can be considered,

it should be realized that only those at the very pinnacle of their profession 

  get into the stellar income bracket."

Variation #5  "Not all celebrities  acquire   bucket loads of cash, because one  must be in the

higher echelons of income to get that much money."

 and on, and on,  and on. 

  (But you cannot beat the original sentence.

It is a clear and straightforward communication of the idea.)

.

However, it is also true that only those who attain the very top of their profession can acquire these huge salaries.