[Stasis5001]

When you get a PhD, you mainly only take classes in your department for the whole time, whereas in undergrad you still have classes in other fields. This usually extends beyond coworkers into friend circles too. This isn't math specific, but more generally to grad school.

Second, programmers at companies almost never work in isolation from other programmers, and in most open office environments are close enough they could touch another one from their desk. On the other hand, a startup with five to ten engineers may be hiring you as their first data scientist, and bigger companies may be putting you on an embedded team, with the nearest data scientist a hallway or floor away. And this isn't a big deal in terms of teamwork, but most data scientists don't have a PhD in mathematics, so if you find higher level mathematical ideas and notation to be the most efficient way for you to think about a problem, your colleagues may not. That's also not a math specific thing though -- an economist, statistician, mathematician, computer scientist, physicist, etc. are all going to have slightly different ways they think about things internally.