If you’re looking for bifl bag I have to give the obligatory shout out to Goruck. The GR1 has molle on the inside that you can attach a holster to and I’m sure that some of the others do as well. It’s a pack that’s meant to thrive in rough conditions and if you happen to damage it it’s covered by their scars lifetime warranty. I’ve had mine for 7 years now with no issues. The only Velcro it has on the outside is for a patch and I’m sure you can remove it if you don’t want it.
@Vej I would look at the Vertx Gamut backpack! I'm not a fan of this American company that tries to act all macho and patriotic while manufacturing their stuff who knows where, because they just say "imported". Instead of "Made in China" or "This is our partner factory in Vietnam at this specific address".
You're not gonna find a CCW bag without Velcro to be honest, that's how you attach the holster. But the gamut seems easy to clean out and none of the Velcro is exposed to the exterior
Have you checked 5.11’s Rush 2.0 line? Is that too much Velcro? I’m not sure what size you’re looking for either. The RUSH12 is great for an every day backpack and small enough to easily fit under an airline seat if you don’t have a ton of attachments.
Maxpedition Urban Assault maybe? Maxpedition's prepared citizen bags are interesting too, basically a jansport with bombproof fabrics.
Osprey, Deuter and similar have good bags too but aren't custom built for carry. Looks normal because they are, and can be surprisingly durable while also being light.
Velcro is out but how about molle loops? Leaning more tacticool for the features and materials or are you looking to be more colorful and inconspicuous?