Summary
Chinese President Xi Jinping reiterated in his New Year’s speech that Taiwan’s “reunification” with China is inevitable.
China has escalated military activity around Taiwan, including frequent incursions near the island and sanctions on U.S.-linked companies over arms sales to Taipei.
Taiwanese President Lai Ching-te rejected Beijing’s claims, stating Taiwan’s future can only be decided by its people.
Lai also criticized China’s restrictions on travel and education exchanges with Taiwan, calling for dignified, reciprocal relations based on goodwill and equality.
I am not going to claim I am a military expert because certainly I am not. I think your arguments don’t hold water though:
It is irrelevant what everyone thought, unless you are asserting Chinese army is as bad as Russian. If so, I would say unlikely on the basis of the entire technological development of both countries. There is also cultural aspect: I worked with number of Russians and Chinese. Russians were sloppy as fuck, nearly all of them. Chinese on the other hand were the most hard working people I have ever seen in my life, again almost all of them. Population size also matters.
Amphibious warfare is only harder until you land and secure even temporary harbour.
You are underestimating importance of western support. “just a few months” is not important - ask yourself where Ukraine would have been now if the US were to not supply anything to them from the very start - and this is the situation Trump is likely to put Taiwan in.
On point two you are correct only if the attacking force has air/sea supremacy like the us did in WWII. With drones I have a very hard time believing that will be the case. That is what makes it hard. Sure landings are brutal, but logistics is a nightmare when you have to supply your troops with vulnerable ships. That is why the Russian navy getting smacked about by Ukraine is so relevant.