Okay, let's be realistic, here. I rarely carry more than 3 knives actually ON me. But every single one gets used multiple times daily. Okay, the SAK rarely gets used as a knife, I keep a special edge on it just because of that, but it still gets used. The necker is my usual 'fine work' knife and my EDC fixed blade most of the time is my shop knife, which has certain aspects of "sharpened crowbar" but a nice convex grind. Given that I work in my shop, it's handy, yknow? I see no reason to take it all off for a quick trip to ace for 3/16 brass rod because I suddenly ran out.
I confess to not often carrying a ferro rod. I'm relatively comfortable with bow drill, and have at least one djeep lighter in every bag, and most often in my pocket, too. Condoms? no. There's a one gallon heavy ziploc and a space blanket in every bag, including my 5 year old son's. But I have my kleen canteen on me. First aid kit? Dude, I have kids. And I make knives. Why would I EVER not cart one around wherever I am? It gets used nearly daily, too. Which means it is always fresh and I always know what's in it.
The best reason to have BOBs set up is so that you don't have to THINK about what to pack. You have 2 hours to clear out? Fantastic! Put the BOBS in the car, bike trailer, pack, whatever- and then add stuff. With a BOB you have basic organization and known quantities.
Now, I personally subscribe to the idea that a PSK, BOB, and what have you are best if they are everyday use items, as well. So my everyday stuff has a few add ons that you wouldn't normally take to walk the kiddos to the store for a treat- like the space blankets. Funny thing is, it tends to make life in general more comfortable. I don't just go from door to car to parking lot to whatever- we do stuff, often spontaneously, and these little survival tools often come in handy.
All of us in the house have given this thought over the past couple years - before that I just put a little baggie of goodies in everyone's bag. The bare minimum is "get me home" which could mean a night out in the countryside (fire, blanket), a fall off a bicycle (FAK),