First off, ignore whatever Xi says publicly. The louder he screams the less likely an invasion is to actually happen.

It's really hard to overstate just how difficult and invasion of Taiwan would be. It would make D Day look pretty small scale by comparison. Taiwan has a US and European equipped military that is completely defensive in nature and has spent 70 years preparing. Calling up the Reserves and they have at least a million man army and probably 20x that number who have had at least some military training. Every person born on the island has to serve. So just to start think about what you need to cross 100 miles of ocean with enough numbers to take on a million man army in a defensive position. Ideally you would like 10 to 1 or at least 5 to 1 but realistically if China used every ship they have they would be lucky to land 100k troops. Of course that assumes any of them make it across the water because unlike in WW2 they will know they are coming and be able to shoot at them 100 different ways long before they approach the coast.

Oh and everyone in Taiwan saw what happened in Hong Kong and they know they are hated far more than those folks. Everyone on the island will either be killed, imprisoned, enslaved, or a lucky few will get to be collaborators. Most of those folks are going to fight to the end and they have weapons and training. Have fun with that.

Of course getting to the coast is just the first step. Taiwan is a mountainous island and I can't imagine what they have built there for defense. It makes Iwo Jima look like a stroll in the park.

Then all of this assumes the US and even less likely Japan just sits back and lets this happen. Either the US or Japan could put the entire Chinese Navy at the bottom of the ocean in a couple of days. Both have better ships with better tech and longer range. Think about the Gulf War when the Iraqi tanks came up against US tanks with double their range and tech. We would block all their communications and it would be a turkey shoot, one Super Carrier Group could more than do the trick. Japan has a sub fleet that would rip China to shreds. That's not counting land based missiles of course.

So assume China figures all of that out and takes Taiwan because we let them. Ok, we simply have to blockade them and take them out of the world market. China would run out of energy in weeks and food within months. They are completely dependent on the US keeping the shipping lanes open. They have no ability to project power either as they only have a few ships that can go more than a couple hundred miles from their coast and they have crap technology.

Oh and this "China is being patient" argument doesn't fly. China is in full demographic and financial collapse right now. It looks like India surpassed China in population about a decade ago but they have been covering it up. It's hard to know just how bad the economic situation is but it is certainly terminal and so bad it's really impossible to comprehend it even if we had the real numbers. This is a country that is imploding. They have put what resources they have into surveillance and controlling their populace so the CCP can hold on to power as long as possible.

The only thing we should be doing is selling Taiwan whatever they need to defend themselves and prepare (unlike Ukraine they are happy to buy stuff from us, we don't have to give them anything). Otherwise we should be assuming the China will go offline at any moment and we should remove ourselves from relying on them for anything. That day is coming and soon so we need to continue to go full force in that direction. We also need to continue to boost our Chip manufacturing here which we were doing with the CHIPS Act (one of the few things Biden got right, even though it was poorly written and full of grift). They way you beat China is to disengage from them, we can live without them but they can't live without us.