>>2760754Packing a shelter is easier than any sort of improvised shelter by a long mile, which is usually done in an emergency or for long-term encampments, even traditionally in some cases.
A tarp is also light, but a bivy is easier to set up and does the job better. Hammocks are not bad, but are not suited to all environments, such as underground or in terrain without a place to hang hammocks.
Ideally, you should be able to quickly set up and pack up your camp, even in a large group. If you are camping somewhere an extended period of time, you don't need to carry your pack to hike, hunt, fish, and so on.