AZ minimum wage is 14.70. If it was 996 and you somehow only got straight time for working 72h a week, it would pay 55000. Assuming there's no overtime exemption it would be $67000. I'm pretty sure it's not a 996 in AZ.

Why does it have to be 996 at TSMC in the US?

Very easily if they need to pay overtime here. I'd be very surprised to find an argument of $37k being exempt in any state.

They will indeed burn themselves out, but that's their choice of work/life balance vs. pay.