I avoided black bags for years because I thought they were the boring default, the thing you buy when you've run out of better ideas. What changed was totting up how many colourful bags I own that never leave the cupboard because they clash with whatever I'm wearing that day. A black bag doesn't have that problem, and I was wasting money pretending otherwise.
This is the bag that works whether you're in jeans on a Tuesday or something smarter for an evening thing, which sounds like a small point but matters more than people realise when you're trying to get dressed quickly. It's also the one that survives bad weather without flinching, which in a city that gets properly wet for half the year is not nothing. Autumn and winter in particular, when every coat you own is a dark colour anyway, a black bag just sits in with everything instead of fighting it. Summer it works too, it just stops being the obvious choice and starts being the quietly correct one.
If you've got none of this in your collection, start with structure over slouch. A shoulder bag or a simple cross body in a stiffer leather, or a good faux leather, holds its shape when it's half empty, which a soft one won't, and that matters because a collapsed bag looks tired by midafternoon no matter what you paid for it. Saffiano style leather, the kind with the little cross hatch texture, is worth knowing about because it resists scratches in a way smooth leather doesn't, and scratches are the thing that age a black bag faster than anything else. Smooth leather looks better on day one and worse by month three. Texture buys you time.
On finish, matt beats patent for actual daily use, patent shows every fingerprint and scuff under certain light and you'll be wiping it down more than wearing it. Hardware in gunmetal or a brushed finish ages better than anything shiny, which tends to look cheap the second it picks up a scratch. Stick to black with black hardware if you want the lowest maintenance option going, it never has to match anything, it just has to exist.
The detail that makes a good one worth carrying is the inside. A lighter lining, grey or tan rather than black on black, means you can actually find your keys without emptying the whole bag onto a counter, and that alone will change how much you enjoy using it.