Before putting clothes and bags in the car, I need to empty them. This is unacceptable stupidity. If you want to build any dependencies of the investments of "nested dolls", then do it. But it is absurd to throw everything out of a backpack to put a backpack (jacket, pants or something else) in the car.
For example: Why count the slots of an empty backpack? This is its possible maximum volume. The backpack should not take up a lot of space empty, and should take up the full volume when filled with something. But he must lie in the car, without the need to empty it.
It seems logical when:

It is enough to realize the regular volume of empty folded clothes and a folded backpack. The same is done with tents. Rolled up empty clothes and backpacks should take up less space. A pattern should be built, for example - you cannot put a jacket in trousers. Assignments must be allocated to be able to place collapsed items in other unfolded items.
It seems logical when:
Tent for 200 occupies 32 places
Tent for 400 occupies 40 places
Tent for 200 occupies 50 places