Been using my turkey vest in lieu of a backpack for better than 10 years. It keeps everything organized and where I can find it. Separate pockets for my binocs, rangefinder, camera and other gear. No time spent digging in the bottom of a pack for some loose piece of equipment.
The game pouch is big enough to comfortably carry my platform, WE stepps, or climbing stick depending on what I'm using along with my camera arm. I can easily climb with it on my back and then I can just pull the platform from the pouch when I get to height.
Once in the tree I hang the vest so it wraps around the tree, at that point all the big stuff I carry in the game pouch is attached to the tree and its empty so it lays flat. The pockets are oriented where I can reach them and there's no additional silhouette in the tree like a full pack.
Something I haven't done but occurred to me this year is I can leave the seat attached (I have always removed it for deer season) and it would make a great knee pad against the tree.