How well someone can solve a whiteboard challenge or brainteaser is irrelevant unless you are hiring someone to solve 10min whiteboard challenges.
Of course the difficulty is how do you assess what the candidate has honestly achieved in prior jobs - what was there personal contribution, and do they seem to have approached things in a way that suggests transferable/general skills that can be applied to the position you are hiring for.
The graphic at the beginning of the article is certainly one problem - the interviewer needs to themselves have the experience to assess the candidate. There is no point having someone with 5 years of experience interview someone with 20 years, assuming you are hiring them for that level of experience.
I think the best interviewing technique is just to go over the candidates experience, from most recent to as far back as you think is relevant, and get them to talk about each project. What was their role, what were their contributions, why did they make the decisions they did, what might they have done differently, etc. etc. Ask them to summarize and deep dive into the architecture, draw it on a whiteboard perhaps.