Never understood why China don't seem to issue optics even on marksman rifle.
Which picture are you referring to?
And are you suggesting that "doesn't seem to issue optics" is a permanent state of affairs, or simply that for a given set of images or a given video, the rifles are not equipped with optics versus optics simply being issued later, in a manner that is not synchronised with being equipped with new rifles?
Every few weeks someone seems to ask "why are new 191 family rifles not issued with optics" if they see a 191 without an optic.
However, they seem to not recognize the images of 191 family rifles (AR, carbine or DMR) that do have an optic fitted.
Furthermore, they seem to be unable to consider the idea that as the PLA are issuing new 191 family rifles, they may not coincide with issuing of optics at the same time, and that there may well be a mismatch -- yet are so willing to believe that is a permanent state.
If we are able to track an infantry unit newly issued with 191s that lack optics, and if they still lack optics issued after 2-3 years, then sure I will concede that asking "why are they not issued with optics" is a fair question.
But otherwise, at this stage it is far too premature.