They absolutely started by stealing things and then figuring out how to make them on their own. But that's no different than how the US built its rocket industry, or how Apple built their OS, or any number of other non-Chinese entities doing the same thing.
Let's not forget the "how it started, where it is now" meme of the whole thing
The United States has invaded more countries than China while having a significantly higher incarceration rate. If anyone is brutal and aggressive, it's the US.
China is sort of doing the same thing with its contemplation of export controls of rare earths and the like.
The British empire tried to enforce no home-grown industries in certain industries among its colonies by law and by dumping or taxes. Didn't work out so well for either the UK or the colonies. This sort of forced competition through export controls may be for the best all around in the long-term.
They absolutely started by stealing things and then figuring out how to make them on their own. But that's no different than how the US built its rocket industry, or how Apple built their OS, or any number of other non-Chinese entities doing the same thing.
Let's not forget the "how it started, where it is now" meme of the whole thing