That was basically my point.

In theory, you could set up narrow flat bars 6" below the saddle and very far forward of the headset, and get a nicely aero position. In theory. But very few commuters do. On many modern bikes you'd need a weird stem (super long and big negative rise). And then what do you do when you want to be upright with your head high?

A drop bar gives a wide range of positions, from low/forward/aero to high/back/relaxed. On the tops is a relaxed upright position similar to the typical flat bar (with the option of interrupter levers). On the hoods puts your hands around 8" forward. Drops puts them around 6" lower. Lots of choices.

When people try to get the same range of positions using flat bars, they end up using trekking (butterfly) bars.

Anyway, I'm not trying to convince you that drop bars are better than flat bars. As mentioned, I've commuted on both. My view is simply that they are very different. That's why I think a person looking for one shouldn't settle for the other.