I'm trying out Tom Bihn Synik 22 as an alternative to my Tom Bihn Synapse (original, now 19). The look doesn't bother me and I like the organization.
The Aer XPac Travel Pack is interesting
https://www.aersf.com/travel-pack-2-xpac-black and more urban wear aesthetic. They also have a Travel Pack 2 Small for petite people. Some onebaggers like the Cotopaxi Allpa.
I often can't use the one-bagger label since I carry a purse + backpack at a minimum so I can put my phone & ID away without having to swing a backpack about in a crowded space. Plus I sometimes bring a packable daypack and foldable grocery tote which makes me a bag nester. I guess I ascribe more to the Ultralight backpacking by weight philosophy than onebag by count, though I like leaving at least one hand free and items must be able to "fast stow" on a plane.
My packing constraints and bag options are influenced by weight as much as it is by volume. That removes many 25L + non-wheeled onebag options which weigh more than 3.5 lbs. If I'm going to 3.5 lbs, I'll figure I might as well add a lb and go for a two wheeled bag like Osprey Ozone or Eagle Creek Load Warrior to keep the weight off my back and feet. I use a Tom Bihn Aeronaut 30 with frame sheet when I really need to pack that amount and don't want to bring a wheeled bag.