Because that's what authoritarians invariably do.

They abhor liberal democracies and seek to extend their domineering control over as many people as they can.

The CCP is an absolutely tyrannical organization that denies their own citizens the rights that you and I take for granted. Why would they ever desire their neighbours to have what they deny their own people?

Look no further than Hong Kong and North Korea to see what China wants for their neighbours.

South Korea only exists as it does today because Western forces repelled Chinese supported North Koreans from conquering it.

Japan only exists today because of American rebuilding after the destruction of Imperial Japan during World War 2.

Taiwan only exists as it is today because of American support.

China would have subjugated these entities and destroyed any chance of prosperity and independence that they had if not for the efforts of people who believe in individual autonomy and liberal democratic values.

China only has the power that they do to day because of authoritarians in the west who tricked the world into thinking that globalism means that we should engage in trade with undemocratic societies.

Because that's what authoritarians invariably do.

Did they invade Hong Kong? It's a very western viewpoint that invasion is the only way to affect change.