Loop is gold value

Conscious I bought this Obejktivdeckel because the lid can be connected by a strap to the camera. The cover is very well located on the lens or a filter.
What is not is revealed to me why the camera manufacturers often refrain from bringing this 1 cent Goodie on the lid. As are placed especially when changing lenses often also lenses with other filter diameter that is quite understandable, but in my view unrealistic.
If I have the choice to permanently remove the cover (eg hiking) down and put it in the hand or pocket or short side to press the shutter to dangle on the camera, then please the latter. Risk losing the cap is thus averted and one has faster the snapshot :-)