Ask HN: Why aren't there more case study type interviews?

Instead of wasting a few days with phone screen, remote technical, then a day of 4-5 interviews, why not just do one screen interview and skip straight to case study that's a couple of hours?

I used to work at a big law firm during college, and noticed lawyers would come and go for interviews and the format was case studies. Lawyers seem to be saturated, and this was how the best of the best (this was a top big law firm) would be selected.

Why can't we do this in tech? For example, if you had some huge performance issues and you fixed them a certain way, you could share the problem with your interviewee and spend a couple hours going from ideation on a whiteboard to putting together a system design or something of the solution. You could gauge how the candidate thinks, and if they've faced the problem before cool and if not at least you (interviewer) know how it actually worked out and can have a technical conversation.

Sorry but at this point in my career I'm kinda done wasting 2-5 days per interview. I'd rather live off my passive income and do something else if this continues lol.