Rather I think that men would abandon such failing society instead.

"Enjoy the decline"? Possible. I don't see it happening so literally myself. At some point the frog is boiling, and something must be done.

They could use sex to manipulate some men to be on their side eg. simps. They could acquire nuclear or biological weapons as a deterrent.

This seems unlikely to me, considering how nothing similar has ever happened. Women have been subordinate to men forever, yet I don't think there's ever been a violent uprising of women.

Also if China and the US go to war, I doubt we will see much of people taking up arms to fight. The countries would nuke each other to death since none of the two countries is going to accept defeat.

Imagine then that it is moonmen invading in their space ships if that makes it easier.