If you somehow think it won’t happen it’s you living in a dreamworld.
The last waterborne invasion of that kind of scale was D-Day and if anything things would be tricker now that anti ship missiles are rather effective.
I mean the communists have wanted to take over Taiwan since 1949 when they took over the rest of China but the sea remains a barrier. It's quite possible that rather than Taiwan falling to the commies, it will be the mainland that gets taken over by democracy.
I think Taiwan needs to show more preparation and resolve. Maybe this election will change things and they will spend more on military. Mostly by stockpiling shells, missiles, mines, and food. Taiwan has advantage that they can build own missiles since few will sell to them.
Taiwan feels like one of those cases where a little ambiguity is actually safer for all concerned than a clear position. You ideally want a situation where the mainland can saber rattle occasionally to keep their domestic audience happy and where Taiwan can sometimes make it sound like an independent state, but neither moves down the track any further.
An invasion attempt by China or a unilateral independence motion by Taiwan would be a disaster for all three parties, the Taiwanese, mainland China and the US.