Backpacking tents should
ideally be around 2.5 lbs. in weight. They should also be compact as well so they can be found inside your backpack or strapped to the outside of your gear without taking up a bunch of extra space. However, since we are talking about budget minded options for backpacking tents I think up to 4lbs is acceptable, but it will cut into your other gear options and you’ll have to make up that weight by perhaps foregoing some other conveniences until you can cut the additional 2 pounds off the tent.
The reasons here are mostly centered around materials. These small tents are compact, and the more expensive tents use higher-cost, higher tech materials to cut weight while retaining the strength and durability needed for serious backpacking.