I would liken it to cars. There is a difference between engineers, mechanics, and mechanics that know a certain car so well that they fabricate parts that improve upon the original design.
Good comparison. Engineers who build cars and understand their intricacies oftentimes just work on one small thing at a time, even in teams. Like a team just working on breaks. The mechanics can piece the stuff together and keep it working in a real world setting. But nowadays a self-declared "AI Expert" in that metaphor might be just some person who knows how to drive a car.
If you think back to when cars were introduced, knowledge of how to drive a car was actually a rare skill! People weren't born with that inherent knowledge, so someone who could operate a vehicle (and do some basic maintenance) was an expert.
Nowadays, that would be laughed at. But AI is more comparable to cars from 1900 than modern vehicles.
