What's your philosophy on a commuter? Cheap beater? Superbike? Steel? Flat bar or drop? Fixie/SS or Geared? Panniers or backpack?
Obviously, a lot of this depends on situation: length of commute, weather, safety of bike parking, etc

For me, I used to have a longer (7 km) commute with a pretty steep climb (on the way home, topped out at 20% grade for a short stretch) so I got used to drop bar, Frankenbike drive train with road shifters, 1x up front, and MTB derailleur (which was much more frankenbike when I put it together, now you can get drivetrains that are designed for this). Then I moved, sold that bike and on my new commute got a Surly Straggler for what is now a 4km commute with only a little elevation change. It's honestly way too nice for its use case, but now I'm spoiled.
What I really wanted was a Cross Check with bar-end friction shifters, but one thing led to another