The British Army after Dunkirk was vastly outnumbered by the Wehrmacht. However, there was this little ditch called the English Channel. The German Army had no experience in large amphibious operations and the General Staff told Hitler an invasion would be suicidal unless Nazi forces had control of the sea and air superiority. Neither of those was ever achieved. Just cause China has a large army like the Nazis did does not mean it has the naval, amphibious, and air forces to get its soldiers across the water and land them successfully on the beaches of Taiwan. Defense by your numerically inferior force is not impossible when you have a large moat around the castle. The Communist Chinese are trying to develop amphibious and naval capabilities and they are making progress. However, it will be years before they have the requisite forces to make a successful landing on Taiwan. https://www.reuters.com/investigates/special-report/china-military-amphibious/
Without practice, without experience, without air superiority, without control of the sea, without mine sweepers, without enough landing craft, without enough anti-submarine destroyers, it is truly mass suicide. Show me a military analysis that says otherwise.