Enforcing a blockade around an island full of long range anti ship and air defences, aided by the US military, is extremely hard. Also and more importantly it’s a very long dragged out war that gives Taiwan time to build allies, and the west to organise, which will make it harder and harder to enforce.
Finally you’re replying to someone saying the war will take a long time, which you initially disagree with then go on to talk about an embargo which more than agrees with it. It’s going to take ages to resolve if they attack and it’ll almost certainly include Russia distracting NATO in Europe. I dearly hope china sees sense and gets rid of xi before his desperation for personal achievements in his lifetime causes the nation and world a lot of pointless suffering