These are fairly standard questions for the "How to Build the Future" series[0]. Sam normally does the interviewing, but in this case he had his brother ask the questions. Sam has been asking a lot of entrepreneurs these same questions (the Musk interview was particularly good[1]). Sam having his brother ask those same questions of him didn't come across as particularly cringy to me. It would have been more awkward if he read the questions and then answered them.
[0]https://www.ycombinator.com/future/
[1]https://www.ycombinator.com/future/elon/