Bollywood vs others in political career

Can any Bollywood star ever achieve success like NTR, Jayalalitha and MGR in politics?

What is the reason for Bollywood stars usually failing in politics and hardly being able to reach any level beyond MP?

If I am not mistaken Shatrughan Sinha is the only Bollywood star to have managed to become a Union minister. Smriti Irani is another (technically she is not a Bollywood actor but a TV actor). Babul Supriyo is another one who became Union minister.

Rajesh Khanna, Amitabh, Vinod Khanna, Dharmendra, Hema Malini, Roopa Ganguly, Arun Govil, Sunny Deol, Urmila Matondkar, Nitish Bhardwaj etc all entered politics but I have never seen any mass appeal for them or higher achievement in politics except winning elections as MPs at the most. Never became ministers of as much influence as NTR and MGR down South.

What is that Bollywood stars lack that they are hardly able to replicate success of their Southern counterparts in politics? Is it possible to see an NTR or MGR or Jayalalitha type successful politician from Bollywood background?

Even when Bollywood stars become MPs or MLAs they seem to be non serious about their political career and often clueless about issues - for eg, Sunny Deol, Hema, Dharam are mostly unable to answer any question on issues in their constituency and visit only at time of poll campaign season. Amitabh also won polls but soon chickened out and ran away from politics post Bofors scam.

Do Bollywood stars lack the skill that their Southern counterparts have displayed in politics? Why, despite their mass appeal and resources, they are unable to do anything significant or become a name to reckon with in politics?