Good job to both Roger and Ivan. Both of these guys are bright, levelheaded and objective.
I hope that Ivan learned a lot from the interview. I don't believe that Ivan has been involved with Bitcoin long enough to have anywhere near the amount of insight that Roger has. I've been following Ivan's channel for a more than a year and it very clear that he's a smart guy. However, it takes some people a while to even consider that BTC may no longer be Bitcoin. After you're open to considering this you'll then be able begin learning more, understand better and then at some point you'll thoroughly (and happily) come to terms with the fact that BCH is Bitcoin.
Please also note that Ivan isn't the first individual to point out that there are more transactions being made on the Dogecoin blockchain than there are on the Bitcoin Cash blockchain. However, please also note that there are less BTC (Bitcoin Core) transactions being made than there are Bitshares transactions, or Steem transactions.
Lastly, I'm glad that Roger brought up the story about the BTC Core developer, Luke Jr., telling customers at a restaurant to not pay for the food with BTC because BTC is not for payments and that they should use their bank cards (sorry Ivan, there's still much more that you're not aware of yet).