Let's take things in order,

Scenarios

Are you trying to prepare for mostly urban situations or are wilderness situations involved? Do you travel to / through / over truely wilderness areas where you might be unexpectedly deposited and isolated? Do your urban situations include truely inner-city urban, suburban residential, industrial / commercial?

It is one thing to survive in a suburban residentail environment with the "shirt on your back" type of preparedness. One can always find an abundance of material for expedient improvisation in a dumpster or un-garded backyard shed.

You can make a knife? I don't doubt that but what has it got to do with a 72 hour emergency survival scenario? If your scenario would be improved by having a knife then you won't have that benefit. Making even a lousy knife will require materials, tools and time that you won't have in the scenario. - this is equally true for all metal tools and most others. I don't doubt that you could unravel the bottom of your jeans and come up with decent fishing line - by day 2 ( but of course you would have to sacrifice some of your jeans to do this and it would be hard without the knife.)

Depending upon the vegetation for sustainence is also scenario dependant. There are few botanists who would be comfortable thinking that they could forage successfully everywhere. The herbivorous wildlife are often brought to extinction due to lack of a particular food which they depend upon. Not everything is edible to everyone. Know your habitat and what grows in it and you can certainly survive on foraging. If your survival situation finds you in a different neighborhood or climate all of the plants will be unfamiliar and you may starve or poison yourself. The beauty of eating things that you have to chase down is that they are almost all edible and they do a decent job of processing the edible foliage that is found wherever you might be. Trust the local wildlife to know what is edible to them. A cow can live on straw but if you try that you will starve - a Goat can eat poison ivy and thrive but it will kill you dead; OTOH if you find a goat or cow that is thriving you don't really care what it is eating - shoot it in the head and chow down! (of course that implies you are carrying a gun and a knife at minimum and it would be helpful if you had fire to cook with as well).

In any situation where you are dealing with social unrest / collapse (such as followed hurricaine andrew or might be found in LA on any given day), a "shirt on your back" situation becomes a practice in Escape and Evasion. Unless you are part of one of the organized (read police or gang) groups or are extremely well armed your chances lie in being unseen, unnoticed, unremarkable in that order.

In a commercial / industrial situation including HazMat there is often no adequate preparation. Having goggles / n95 or better face-mask might help but short of SCBA gear you will probably be SOL.

In building collapse situation a whistle on the key-chain could mean that you are the one who is dug out first. Having leather gloves could mean that you are able to save some of your cube-mates.

In a wilderness situation there is no making metal tools. If you don't have a knife you probably won't be making wooden tools either. In wilderness, if you don't have knife you will be reduced to shelter and fire. And you won't have fire unless you practiced before hand. Friction fires are not easy to create. If you pin your hand behind a large stone and don't have a knife your vulture food.

There is a great deal to be gained by having the knowledge to enable you to improvise. But without the wisdom to know the limits of improvisation you are only setting yourself up for a nasty surprise.

My approach to streamlining my EDC is to carefully consider the possible scenarios for any given adventure and carry what is required for that adventure plus a minimalist set of gear that will help if something unexpected happens. If I am carrying something for the adventure that would be redundant with some of that minimalist gear, I consider leaving one of them behind.

So what am I carring today.

Scenario is commute through rural / suburban / residential / industrial to 1 storey office building in suburban / rural fringe zone to sit at a desk all day.

Altoids PSK in front Left
Altoids FAK in fron right
100' flat spool of twine in back left
wallet in pack right
Cell phone on Left hip
Leatherman Wave on right hip
whistle on each separatable section of my keychain along with swiss-tech utili-key and swisstech microtool+ and ASP saphire light
2 Butane lighter
Another mini-multitool with pliers, file, LED light, Blade, Screw-Driver.
Book of matches and pack of smokes.

I have carried atleast this for the past 2 years and I don't even find that I notice it. I rarely get more attention for this gear than I get for my 3 inch long beard or my fedora. I am able to carry this and more if I am in a suit. In a jeans and tee-shirt I am limited to only those four pockets and my belt.

If you think that is a lot you should checkout my vest gear, which I wear whenever it will be cool (temperature not style) enough.