Salman, Shah Rukh and Amir khan are undoubtedly considered the kings of Bollywood. You can attribute that to their mostly successful films, years of experience with scripts and just their general aura when it comes to stardom. But believe it or not, they are actually at this big a stature because people like you and me watch their films. It’s really that simple.
Now, to answer your question, stardom comes only when you gain a fan following who support and love your work. And as long as that following goes to the cinema to invest their money into watching your films, you will continue to be successful and gain more fame. This applies to the three Khans too. The day, people stop enjoying/ watching their films with as much intensity, they will stop dominating Bollywood.
Alongside their on screens depictions , its their off screen picture which have made them an overwhelming character .
Aamir who has been here for over 25 years and done under 50 movies , is known for his 'savvy' decisions and 'excellent' film advancement abilities (Whether it is raising voice for Narmada issue when the arrival of Lagaan was close or giving each staff in a multiplex a 'Ghajini' hair style when the equivalent was going to discharge).
Off screen, he has a picture of 'The Intellectual' , on account of his remain of saying "NO" to paid honor capacities, again his selections of movies e.g; Sarfarosh , Lagaan , RDB , Taare Zameen Par and so forth what's more, not to overlook his TV show Satyamev Jayate additionally his ongoing interpretation of the 'Bigotry' issue (which is again easy to refute yet not applicable to this inquiry).
Salman had a kickass start in Bollywood and a significant decent time initially however later on his beneath normal motion pictures and his off screen 'terrible kid' picture followed by numerous shocking legitimate difficulties pushed him on a back foot. Be that as it may, he despite everything had a hang on the crowd ;on account of his 'family film' picture and the talented attractive face , appealing body and his executioner eyes. Post the year 2000 when his life took a take off with Wanted and his image Being Human came in picture . Also, Since then Salman is the most gainful brand to put down his wager on.
Shahrukh then again has an immediate advantage of his on screen picture. A talented and energetic entertainer who has an insane fan following, for the most part females (shockingly in each age gathering), due the sentimental character he has lived in film. Off screen he is increasingly dynamic as a specialist ; whether it's acting in Marriages, Family Functions , Award appears or claiming an IPL group and a creation House . He is likewise known for his witted character with a decent comical inclination and furthermore for battling with Salman on different events and mishandling a security watch at Wankhede .