Question

Why did Buddhism four noble truths and rightful path most likely appeal to so many people

Answer 1

I would say that these ideas most likely appealed to so many people because they promised a way for people to end worldly suffering.
People were sick of seeing other people, including themselves, suffer every single day in this rotten world, which is why they wanted to seek help somehow. They managed to find it in Buddhism, which recommended walking down the rightful path in order to end suffering and pain.