We are used to living in countries where people have rights. We have constitutions which guarantee citizen these rights and make the governments subservient to the population. Our government is elected by the people directly or indirectly and technically works for us.
This is not the case with China. In China, people have no innate rights. Any rights they have, are given by the ruling body, whether it is an emperor or its continuation, the CCP.
For China, what they are doing in Hong Kong is completely normal. They have been doing the same to their own mainland population for thousands of years and the changeovers from monarchy to communist party is basically cosmetic.
China does not recognize Human Rights and so it is difficult to say they are "breaking" them.
It is a construct we made for ourselves in countries that technically the people are governing themselves (ie democracies).
This is an abstract concept in China. Just as if Iran started accusing Canada of breaking Sharia.
Now, don't get me wrong, I am not absolving China of the crimes they are committing. Just because something is legal in China doesn't mean it is not a crime. We can and we should react to this and try to bring basic rights to Chinese people.
But it is much more complex and delicate problem than people try to make it.