Technically, all social interaction is just conversation, but there's different kinds of conversations, with different goals and intricacies. The podcast convo is usually "what do you think about X?" and even autistic people are good at that, just talking about what they're interested in. However, you might be surprised to find out that most people get turned off by long-winded discussion or debates, it will seldom make you the coolest guy in the room for knowing a bunch of facts. It's very impersonal, to say the least, and you often step on people's toes if you're disagreeable.
Consider the basic rapport building kind of conversation, when you need to get to know someone better. The goal is different, you're supposed to find common ground and sort of implicitly affirm to each that you're OK, trustable etc. In that case, you're not going to go off into any kind of controversial topic, because 9/10 people will think you're being a deliberate an asshole and attacking their beliefs or interests.
Then consider maybe flirting (yes, irrelevant for a wizzie). It consists entirely of trying to convey sexual/romantic interest, without outright saying it.
There's all kinds of intricate games people play. It's really simplistic to think that's just a back-and-forth and saying what you think.