It's not rich. It's literally caste. Even Bhishma and Drona prevents Karna from a duel with Arjuna because Arjuna is a kshatriya prince and Karna belongs to a lower caste. That's when Duryodhana gives him a small kingdom. Even that wasn't enough to make him eligible coz caste can not erased with wealth
Whatever were Duryodhana's faults..he was such a good friend ❤️ and for someone like Karna who had faced so much discrimination and mockery..this was such a welcome change that he found someone who stood by him
 
 
 
 
 
 
 
 

 
 