2) Taiwan does not represent unprotected border territory. Heck, attacking it sustainedly would require significant and slow naval logistics
3) Other than human intellect, there is little in the way of natural resources to obtain out of Taiwan. It's economy is manufscturung and export driven.
Other than some nationalistic pride to recapture teritority, they are not much alike.
To add, Taiwan uses traditional Chinese and is more conservative to traditional Chinese culture. China abandoned all of that during the cultural revolution. There's been a recent nationalist push to embrace "traditional" Chinese identity, involving mainand Chinese people going to sites in Japan and elsewhere wearing "traditional" Chinese clothing. Imagine the nationalistic outrage if someone wore a kimono in China. In practice, these traditional Chinese clothing are cheaply made cosplay from Taobao
Why do people keep spreading misinformation?
E.g. Taiwan grows and produces some of the best tea and coffee in the world. High end tea leaves costs more than some stock grants here. China tried for years to replicate it and has some success but definitely still far off.
Taiwan is renown for many things - not just semiconductors. It's just you might not know about it. A lot of your every day life might have something to do with Taiwan.
Existing US land and sea based nuclear weapons could hit targets in China in a matter of minutes. Being based closer to China/Taiwan might shouldnt matter in the age of ICBMs.
I'm not defending autoritarianism or communism, but I think you're just not putting yourself in their shoes and looking at things from their POV. They supress other viewpoints not because they're afraid to be shown wrong, but because they believe it's best to supress them and not have people confused by enemy missinformation.
(Not an expert, but this is my impression from talking to both chinese and vietnamese people who defend or at least don't oppose their communist governments, and also spanish autoritarians who defend the Francoist regime. I used to think they were brainwashed/dumb/evil, and now I think their worldview makes a bit of sense, even if it's still misguided.)
To the extent that party elite started building their own, parallel universe of food, summer camps for kids, apartments, shops, etc. closed to the ordinary people. It was clear to many people that the Soviet road, as followed, goes to a variant of a North Korea lifestyle.
I have a strong impression there are similarities with Russia and Ukraine. Having a neighbor with a similar culture and overlapping histories that also has independent, democratic government was likely viewed as a direct threat to the Putin regime and one of the driving reasons for the invasion. I could see a similar calculation with Taiwan/China.