I commuted 15 miles (24km) one way to work for a long time, about 30 years, and experienced a few things along the way that have directed by cycling ways.
1. As I became more fit there was less perspiration. By the end of summer the first 12 miles were essentially sweat free.
2. Flat bar bikes were uncomfortable as there were not enough hand hold positions to relieve strains on the wrists.
3. Road bikes are fun commuters, especially a road touring bike.
4. A modified mountain bike is the near ideal commuter. Change bars to drop bars and adjust stem for reach accordingly.
5. Ebikes are fine for some individuals, however if you don't use the muscles by pushing them the road to fitness is longer and limited. (docs words, not mine, so don't flame me!)
My experience says a high trail bike is very stable and preferred commuter. My main commuter has a trail of 70, 43 chain stays, and drop bars. This particular bike is a custom made to fit me, but is modeled on the first generation Kona Jake the Snake. To this day it is still my favorite bike to ride, and I have plenty other offerings to choose from. The road touring bike is another of my favs, again it is a custom made to fit me, but is modeled on the Giant Anthem from 2010, but has drop bars. Supremely comfortable ride, and again a high trail of 70.