I think this is true in some things and less true in others.

It's a pretty high moat getting into stuff like simulation software because the people working on numerical methods overwhelmingly have PhDs and it's a mixed skill set. Domain expertise here requires you to know maths to a high level. Even mechanical engineers often struggle here; it's often applied mathematicians and physicists turned devs that work on this stuff.

I worked on a fairly gnarly signal processing thing a while back that required bringing together knowledge of physics and software and maths and I found explaining it to people was tricky as their eyes glazed over at some point because their knowledge typically only covered one part of those.