IsThatBrothaMouzone?
Superstar
Even Leo isn't guaranteed to pull in a smash. J. Edgar was a flop.
Leo does have a lot of successes, but it has more to do with how discerning he is with his roles. He has only made 8 movies in the last 10 years, and all of them were with top notch directors. I mean he won with the Revnant but it's been three years since then and he hasn't made anything, only now coming back out to work with Tarantino again. We'll see if his star would be as bright if he was making 1-2 movies every year like other "stars" do.
This is very important. The top stars have a knack for picking out challenging roles that also have some commercial viability. Guys like Denzel, Leo, Tom Hanks etc., you know that worst case scenario, their movie will be a 6/10 or 7/10 just on the strength of their acting.
Younger actors today have been brought up in the Franchise Era. They get off to strong starts because they're featured in big budget franchise flicks and everyone THINKS they're bonafide stars. However, once they branch out into other kinds movies...it becomes clear that they lack a certain "it" factor. Their commercial success was driven by the name of the movies they were in, and NOT their innate acting ability. Back in the day, A-list actors had to climb the ladder one movie at a time. They had to take lots of roles and shine wherever they could to get bigger and more lucrative deals. Many of the stars today are given the bag first and then try to take on more serious roles later. If you haven't been prepped for meaty roles through extensive theater/TV/small-budget movie experience, it's difficult to ramp up later on.