Except some of us already have full-time jobs and don't want to spend the weekend working on quizzes, whether it's paid or not. And unless you're very generous with timing taking a day off of work can be a logistical issue, not just a pay issue.

This type of interview self-selects for people with fewer family/non-work obligations, who are willing and able to spend their free time still programming.

We aren't paying for the work-product, we're paying for the time and inconvenience. It's more to show respect for the candidate's time than to actually "hire" them to do an interview.

I mean, even "discount" recruiting platforms like Hired and Vettery will cost 5-figures when we make a hire through them, and traditional recruiters often charge 20% or more of the new-hire's first year salary. A few hundred bucks to get some more information about a prospective coworker is cheap.