Earlier quoted context omitted.
If your friend was not very senior (10+ years experience), I would not believe what he says, since he probably did not have enough experience to judge the situation. I think the idea that the game industry is "behind" other fields is kind of comical, given that games are some of the most complex software in the world, and big game teams have only a few hundred people on them, and meanwhile something relatively trivia…
TDD might not apply well to games because they are used by big corporations for 15 or 20 years. It makes more sense when you're working with old legacy code and you want to add features to it. Unit tests are definitely not a all-around solution but they have their use cases.
No!!
Testing is not merely about future proofing (although it's a really nice benefit), it's about proving that your code actually works now. By writing tests and verifying that they pass you can be sure that the code actually does what you think it does. Furthermore you can ensure that when other parts of the code changes your code still does what you think it does, which might be an issue tomorrow, next week, or in ten years.
\* note: Testing does not prove that your code is correct, only that it satisfies the conditions of the test. As with all engineering testing is only effective as the person implementing it.