It’s impossible to say. What does he say regarding what? And what do you consider is worth debating over. It’s usually not Joe’s opinions per se but the guests.
His podcast literally covers everything you can think of. Indigenous people, hunting, technology, different diets, archeology, random chatting with comics, or otherwise interesting people (according to him).
Usually the guests are experts in some field and tell their opinions on whatever matter they have a degree in or they just talk random nonsense to make dialog that some might find interesting.
Sure they are, depending on the subject of course. Someone with a phd in mathematical physics from Harvard talking about physics would be considered an expert in the subject no?