If TSMC doubled or 10x what they charge Nvidia on Monday, Nvidia can’t switch suppliers overnight, and it would crash Nvidia’s valuation, leaving TSMC to say “ok we have the capacity for anyone who wants to take on Nvidia”.
Another side of that, while the whole “China invading Taiwan thing” isn’t exactly on the cards, there’s now $1+Trillion at stake shorting Nvidia stock alone if China felt like putting a few boots on the ground for a week.