I live in a large city metro area (Chicago), and theft has been a concern for me forever. Some of the most versatile "stealth" bags I've used are a number of different sized ballistic nylon tool bags.
They're not padded, but I don't throw my gear around, and haven't dropped a camera bag in 30 years and don't plan on doing so in the foreseeable future. They open up wide, so it's easy to pull anything out and root around inside, and they always have a number of internal and external pockets. They seem to always come with a shoulder strap, but I've got a few padded straps that I like that I can easily attach to any of these bags. Instead of dividers, I use neoprene lens sacks to keep the lenses from being damaged from banging around.
They're not stylish, but they are easily available, cheap, durable, and available in different sizes depending on how much gear I want to carry. I linked to a pic of a Craftsman because it was easy to find online, but most of mine are no name, and have different colored panels, so look like they just house dollar-store throw away tools instead of thousands of $$ in camera gear.
Scott