Yes, that’s how China sees it. Other countries see the creation of artificial islands and reefs via dredging and landfill as a pretext to restrict navigation in the South China Sea. It’s complicated, hence sort-kinda.
China's aim is, quite clearly, to prevent the US Navy from operating in the South China Sea in the case of a war. That's not a question of freedom of navigation, and the US "freedom of navigation" operations have to go out of their way to go near the islands China claims.
China is additionally interested in the resources under the South China Sea, just as all the other countries that occupy various islands and reefs are. This, again, is not an issue of freedom of navigation.
China isn't about to block shipping through the South China Sea.
