Hitler couldn't cross the 50 miles english channel back in 1940.... the operation 'sea lion' was doomed to fail. Even the Allies' normandy invasion, was hard and it took total sea and air dominance. China could surround Taiwan and blockade it, but it can't keep that blockaded is itself it would be blockaded by the US and totally sealed internationally. It will be starved economically.
Also, keep in mind, during the cold war, USSR had to give up the sealing/blocading of Berlin, as the US kept supplying it with food via air. The US could have given it away, as it was far from the West's border, but it didn't.
The US will do the same this time, as the public from both sides of the political spectrum, are very against CCP. The only people that string along with China, are some elite media companies like Disney, NBA and of course Apple.
The average Joe doesn't like that their job went to china, and they would be glad if the US put up a fight.
"Carefully compare the opposing army with your own, so that you may know where strength is superabundant and where it is deficient." Sun Tzu