Countries willing to pass on a US patent to China stop getting the chips (or, in this case, chip-making jobs, realistically, but that still hurts)
Also Taiwan doesn't wanna help China and even if a US sanction was just an excuse to hurt China and get away with it they'd probably do it.
Edit: in this case, this chip is "foreign-produced items [...] that are the direct product of U.S. technology or software", according to the article. I feel it was implied but clarity is always good. US technology, used with permission in a Taiwanese good, and that permission could be retracted.
Companies collect a bunch of telemetry about everyone they can, that's the basis of their ad revenue. The data is used to identify you, your devices, and your preferences, and is called a digital fingerprint.
They also use this fingerprint to detect people doing things like making an account to avoid a ban.
Your fingerprint, when you made a reddit account at work, will have virtually identical devices attached as anyone else using reddit at work. Lots of people have alt accounts for normal reasons, so Reddit decided yours and someone else's belonged to the same fingerprint, probably since you made the account.
But now they got banned. Maybe even got caught actually using a second account to circumvent it, and reddit is cracking down on the whole digital fingerprint because that's "you".