Ugh, I can't not agree with you. That's true. So except PRC want to flattened Taiwan (which is basically not in PRC agenda), it's hard to do it. But I still believe that PRC will attack Taiwan if they declare "De Jure" independent.
But, why PLA have to send their ground troop before the sea is safe?
The Sea is never going to be safe as the sea does not just guarded by the Naval Element, First, you have Taiwan own Island chain (Penghu, Kinmen and Matsu Island) that Chinese need to take before heading to Taiwan, simply Guns on those Island can shoot at ships crossing over the strait, SAM on those island would take down transport and PLA Troop have to take those 3 island before the grand assault, and that will divert resource such as ship, manpower and airpower for 3 miniature Invasion.
Then Come between those Island and the Main Island, Sub would be a problem, and also Missile, Guns, SAMs and Aircraft Based near the coastal area would be a problem. Also, since Taiwan knew the intention by the preceding invasion of the outlying Island. The Taiwanese would simply mine the approach. And all these you cannot touch until you have infantry on Taiwan Soil. Even then, China could most likely achieve Air Superiority but not Air Supremacy that mean the Air Campaign over Taiwan will be impeded by the ROCAF, and if USAF were involved, then I don't think China can achieve even Local Air Superiority, and the airspace between China and Taiwan will be contested.
It quite depend on Taiwan on whether or not they will declare dejure independence, the question is always, why? They have a good thing going on now, both China and Taiwan, why would both or one of them want to upset the balance??
As I said, eventually Taiwan will reunited with China, and that contrary to most Chinese member think, it would be on Taiwanese term, unless it's like you said, China wanted to flatten Taiwan, but then what is the point of reclaiming a flatten land??
