vest or chest pack?
It depends on the weather and where I am fishing. Hot weather gets the nod for the lanyard. Small fly box with enough flies selected for the day. If I'm fishing in cooler weather, I go with the vest. I don't own a chest pack. I find that I carry too much junk that I never use on the water.
The perfect example of a minimalist is a friend of mine. He fishes with a fanny pack with a bit of tippet and leader material and a couple of plastic snuff cans with some flies. And he catches trout!