There are definitely times when we have more gear with us, and sometimes when we have even less. But Tunas bag is a great example of taking just the essentials for a nice Summer day of fishing.
Often times we are fishing a new spot and we aren't totally sure what will work so it is nice to have options. That is when we will take more flies. Or other times on certain rivers where the fish are very picky with the hatches, we might take an emerger box, and a separate box with adult mayflies. But the vast majority of the time we carry around a bag similar what Tuna showed us.
“You might be out hiking, backpacking, camping, or riding your bike around and you don't always need to take the full setup.”
On the other hand there are times when it makes sense to take as little as you can get away with. These opportunities are so much fun because you take hardly anything and you see what you can get away with. It is so rewarding to pack a little bag on a bike ride and end up catching some fish with it.