1) A lot of places combine sick time and vacation time. You can be sick if you want to, but that means your beach vacation just went out the window.
2) A lot of people are working from home — some employers take the position that they don’t want you spreading germs, but you might as well keep working while you’re sick. “You’re not in the hospital? Good! I need these reports by 3 PM.”
The government pays for the 80 hours in the form of a withholding tax credit for the business. It is a provision in the Covid relief bill.