Uruvela Kassapa in the Vinaya Mahāvagga

Reading about Uruvela Kassapa in the Mahavagga. This kassapa keeps saying, "But he is not an arhat like me." In a way it's a doubter of the Buddha, but proving him wrong by miracles is the wrong way to go to my modern sentiments. The Buddha confronts him and he just snaps out of it. I'd like more information. Just like I'd like more information about the gradual teachings that converts Yasa, his father, mother, and his father's ex-wife (nice detail there). In a way what comes down to us is pretty sketchy. It can fill up a bookshelf, but it's so ancient, it's hard to get through to it. I'm trying though. Someone asked on Reddit if as a Buddhist you really had to read the Pali Canon. I'd say you don't have to, the only have to is uttering the refuges and precepts, but as others pointed out, couldn't hurt.