Well, you have greater insight than me given your background so I respect your POV.
I am of the view that modern warfare is increasingly hybrid in character and difficult to fight by extension. Even a moderate country can fight very well if it is motivated enough. Taiwan is much better equipped to fight a war than Ukraine.
PLAN, in its current form, can insert thousands of troops inside Taiwan in theory but a much larger force might be needed to occupy and control the island. PLAN will have to deal with Taiwanese cruise missile, mines, and defensive formations in the process. PLAN can try to soften Taiwanese conventional defenses with jet fighters, cruise missiles and ballistic missiles but as I pointed out before - numerous Taiwanese defensive positions are in mountainous locations and have the capacity to absorb lot of firepower - these formations cannot be cleared in some days (very likely to last much longer). Chinese armed forces can certainly batter and slice their way through Taiwanese conventional forces but they might have to deal with unexpected combination of guerilla warfare and urban warfare when deep inside Taiwan. Taiwan is home to millions of people - their motivation and courage will make difference in the end. These people cannot just pack their bags and leave - all the more reason to fight. Human factor.
WE can discuss this theme some other time though.