We learn in the last line that Roma is actually bribing Williamson to get the leads he does and in his final lines looks at Levene's success as a way to get part of Levene's wins while sacrificing none of his own. This is arguably the performance Pacino should have gotten the Oscar for in 1992 not the over the top work that ending up winning for Scent of a Woman. Roma walks away completely intact at the end of the movie, completely untouched by the sliminess that he mocks the others for because he is superb at it and thye are failures.
The entire cast was maginficent and Jack Lemmon gave one of his greatest performances in a long and storied career. Harris's work was less surprising because even then he always had the ability to be one of our greatest actors. And Arkin, who until that point was known far more comic performances than dramatic ones, gives one of the most undervalued performances in a career where he was never given full credit for his talent.