The 1099-K is meant to ensure that those that do business online report their income.
https://plantingmoneyseeds.com/3-things-your-home-business-should-know-about-the-paypal-1099-k/
.
If I remember correctly EBay/PayPal, (EBay at the time owned PayPal), was forced by the IRS to send out a 1099-K to sellers that sold items that totaled over $20,000 or 200 transactions in a calendar year period. More importantly A 1099-K had to be sent to the IRS. Problem was the number of people that did not have an actual business on file with the state and or local governing body. They didn’t have a state sales tax permit or a federal ID number for the business. Why would the state let alone the IRS worry about some guy running a small business out of his home? The government wasn’t getting their piece of the pie. With the 1099-K not only do they get their due income tax and state/local sales tax money they know who might be running a business under the radar of the IRS, state, and local government. It’s all about getting their piece of the pie.
As for the OP’s friend I would be willing to bet he will get a 1099-K from PayPal. PayPal knows nothing about where the guy got the merchandise he listed on EBay that sold for over $60,000 so far this year. He will then have to pay the person who prepares his taxes to straighten out the mess with the IRS. One thing for sure I wouldn’t just throw the 1099-K in the garbage can when it comes.
.