Why was antony's speech more effective?

It really boils down to emotion versus logic. Brutus appealed to the crowd’s intellect. He gave a rational, prose speech about his love for Rome and Caesar's dangerous ambition. It was a solid argument, but it was cold and abstract. It asked the people to think.

Antony, on the other hand, aimed straight for their hearts. He masterfully used irony, repeating “Brutus is an honourable man” until the phrase became a bitter accusation. He used powerful props—Caesar’s will and his bloody, torn toga—to make the murder feel personal and visceral. Antony didn’t just present an argument; he created an emotional experience. He turned a crowd of listeners into an enraged, vengeful mob, which was far more effective.