I'm dead serious when I say it took my players hours to create level 1 characters for Doomsday Dawn, while I'm consistently able to help rush out level 5 martial characters in 20 minutes or less in 5e.
20 minutes sounds really slow for a first level 5e character. Really slow.
It's not a matter of lack of experience, or even a fault in the system. We take our time, we joke and catch up, we rummage for feats and concepts.
Well yeah, but there's a serious difference between it taking someone two hours to make a character and someone spending two hours making a character because they're talking over concepts and hanging out with their friends.
I've spent hours talking character ideas in a simple d6 game before. That doesn't mean simple d6 is a game that takes hours to make a character in, however.
You're basically talking two entirely different activities.