I've heard the same excuses from ML engineers before introducing tests there, embedded engineers, robotics engineers, systems engineers, everyone has a reason.

The real reason? It's because writing tests is a different skill and they don't actually know how to do it.

Oh that's crap. I've been a software engineer for over 30 years. I love tests - I preach testing at my current place of work. I've also worked in games for about a decade. Testing in games is... not useless, but very much less useful than it is in general software engineering.