If China attacks Taiwan, they are attacking another country. Just like Russia attacking Ukraine. Doesn't matter what psychobabble a dictator spouts.
Psychobabble or not, it boils down to how much anyone wants to get involved in a nasty fight to save someone else, which might end up causing more damage to Taiwan even if they do. I don't think this is right but is the world has always operated, not sure anything has changed.
From a day-to-day perspective, they treat each other as separate countries in practice, if not in name.
You are right the KMT has now lost 4 presidential elections in a row and the tides are changing. But they still are the majority party in the legislature and will continue to exert tons of control.
My claim is only that Taiwan needs to pretend it still feels united with the mainland to maintain the political farce and keep Beijing happy. That for Taiwan to claim independence would be a political game of chess as then that means Taiwan is no longer just a breakaway province in rebellion - it's actually succeeded.
Maybe officially you are correct but you can't claim the above has no bearing on the relationships between the two nations.
It's the exact same rhetorical playbook Putin used with Ukraine.
They believe we need a reminder that our elite are not much better and that the alleged ethnical cleansing of Gaza is such a timely reminder. As a way to not get us dragged into yet more wars.
I guess.