Arnold is an icon who made iconic movies, played iconic characters and delivered iconic lines.
Johnson has appeared in over budgeted, low performing, forgettable films. He even played a white guy at one point. Adjusted for inflation, Arnold earned more.
Arnold started from scratch and conquered bodybuilding, cinema, and politics. Johnson was born into a wrestling family and had a huge head start. Johnson will NEVER make it in politics.
Conclusion: Arnold was and is The Man. Johnson hasn't surpassed shit.