I used to think the same many years ago, but I switched over to favouring the trail-weight without bags and pegs, the reason being that experienced backpackers will rarely use the supplied pegs anyway and will always take their own selection. Actually many manufacturers now quote both the trail-weight and fully packed weight with supplied pegs etc.
I could never understand the term 'trail weight' as if you would take the tent 'on the trail' without pegs, poles, guy-lines etc.
I have noticed that the Chinese copies tend to be quite detailed and give you the weight of each item so you can add up whatever you plan to use.
Example for the Naturehike Mongar Ultralight 2 Person Tent.
Used as a freestanding tent it is very simple at the same time. Light weight material and rationale structure lead to suitable Pack Weight.
Balance the stability, comfort and weight. More space, enough for 2 people. It can resist the wind in all directions. Good ventilation, 2 air vents on the both side of the outer tent Those Elevated weight in return for stability, comfort and confidence. Use It can work in most cases.
Car Camping, Hiking and Mountaineering.
Product Dimensions Tent Size: Full (70 + 135 + 70) x210 cm. Height at the highest point 105 cm.
Inner Size (Height x Width x Depth): 210 * 135 cm
Tent Weight list Outer tent: 624g Tent Interior: 539g Pins: 594g Plug and rope: 84 g Mat: 249g