Bingo, PRC is not going to start amphib ops until TW has minimal weapons that can repel invasion left. They're not stupidly charging into a Normandy because they have magnitude more radars, missiles, drones etc, enough to make sure TW won't have much of theirs for long. TW is an island 16x smaller than UKR, much larger gap in MiC production vs PRC than UKR vs RU, and unabled to be resupplied via porous land borded by friendlies. TW also thoroughly covered by PRC ISR, including SAR to look through foliage, nearly every inch of which can be hit within 7 minutes with PRC rocketry. Less once PRC establishes persistent drone presence. It's why all the recent analysis depends on TW buying enough time for US+co to enter picture.

The flip side of a contested amphib operation is an uncontested one, which is potentially siginifantly easier than land invasion because there's no where for defenders to hide / ambush. Crossing a shallow strait where subs can't hide is probably easier than US plowing through Iraqi desert where defenders can at least pretend to put up defense by entrenching tanks / digging trenches. It's basically untested sailing if PRC destroys TW platforms that can hit back and lock down with air supremacy.

Also folks should look up TW river map, TW island is broken up into a series of bastions cut up by rivers where connections / bridges can be severed and sections attacked piece meal. If PRC's smart, they'll destroy most of TW weapon platforms that can reach out into water, bombard a few km of map squares of landing site to dust, have drones shoot everything that moves 5km out to carve a landing zone that can't be contested by large or small fires. If PRC smarter, they'd just blockade TW until world realize the only country with enough sealift to supply an island of 24m with food and water is PRC.

As for taking urban centres, look at how Israel is doing in Gaza with 20x population density than TW, theoretically urban combat is suppose to be slaughter vs attacker but if you indiscrimantly bomb and starve the population until they can't put up organized high end fight, then it becomes a managable problem. And again if PRC smart and they have to land boots on ground, they'd likely just siege from outside urban centres and small fires range, and wait for factional struggle and find collaborators willing to do boots on ground enforcement in return for controlling food + water.