This is incorrect. There are lots of ETFs that now directly hold China A shares. CSI 300 index is the equiv of S&P 500 in mainland China. Also, via HK Stock Exchange, you can buy China A shares via "northbound connect". A broker like Interactive Brokers supports this type of trading and the bizarre/special currency (CNH) required for it. That said, I excluded China because it is not developed and has awful transparency.
And if you look at the composition of the indices and ETFs you realize that you aren't participating in the innovative China, but get typical developing country stocks and very limited exposure to innovation.
Also -10% over the last 5 years vs. +103% for the S&P500