You don’t run it for everyone, just people who seem good enough and are willing to do it. A resume filter and a 30-minute conversation are usually enough.
You stop as soon as you’ve got your hire. If you’re bad at picking people for the screen, you learn the signals quickly because of your level of investment.
It does replace a longer traditional interview loop. You hardly talk to them up front. You tell the candidate you will extend an offer right after the work phase.
Another objection is not everyone can afford to spend that time with you. That’s true. We would pay them, and still got some refusals. You have to accept that every interview style works better for some candidates than others. You’ll also find candidates who love it.